Source: WASHINGTON STATE UNIVERSITY submitted to NRP
FIBER AND STARCH POLYMER INTERACTIONS: A FUNDAMENTAL APPROACH TO IMPROVING THE QUALITY OF HIGH FIBER EXTRUDED CONSUMER FOOD PRODUCTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
AFRI COMPETITIVE GRANT
Reporting Frequency
Annual
Accession No.
1014948
Grant No.
2018-67017-27564
Cumulative Award Amt.
$449,523.00
Proposal No.
2017-07669
Multistate No.
(N/A)
Project Start Date
Feb 15, 2018
Project End Date
Feb 14, 2024
Grant Year
2018
Program Code
[A1361]- Improving Food Quality
Recipient Organization
WASHINGTON STATE UNIVERSITY
240 FRENCH ADMINISTRATION BLDG
PULLMAN,WA 99164-0001
Performing Department
Food Science
Non Technical Summary
Consumption of high-fiber foods has been linked to reduced incidence of obesity, yet their acceptance is low due to poor sensory qualities such as being overly gritty and dense. This issue has caused the vast majority of products to be made with refined grains that lack the nutritive properties of insoluble fiber.This project will explore the fundamental aspects of the internations between the insoluble fiber and the starch on both a macro and micro levels. The understading will be further used to develop and test starategies to make high fiber extruded products that would still retain the sensory attributes that the consumers desire. The outcomes of this research can be utilized by the food industry to develop products with higher fiber and good texture.
Animal Health Component
25%
Research Effort Categories
Basic
70%
Applied
25%
Developmental
5%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5021599202040%
5021099202010%
5020999202010%
5021599200020%
5021099200010%
5020999200010%
Knowledge Area
502 - New and Improved Food Products;

Subject Of Investigation
1099 - Tropical/subtropical fruit, general/other; 0999 - Citrus, general/other; 1599 - Grain crops, general/other;

Field Of Science
2020 - Engineering; 2000 - Chemistry;
Goals / Objectives
Our long-term goal is to develop a set of processing strategies that increase the consumer appeal of high-fiber foods and lead to their increased adoption in the average diet. Our goal for this proposal is to determine the relationships between surface characteristics, firmness and particle-size distribution of insoluble fiber during extrusion processing and how they relate to the expansion properties of different starch types. Our hypotheses are threefold: (i) that stronger starch matrices, such as those found in waxy wheat, are more capable of expansion and hold more fiber particles without adversely affecting texture; (ii) that insoluble fiber can be physically and/or chemically modified to better interact the starch matrix without breaking the cellular structure; and (iii) that, under the right circumstances, the addition of insoluble fiber may even enhance the expansion of starch.We will test our hypotheses by generating extruded products that incorporate four types of starches (native wheat, waxy wheat, native corn, and waxy corn) and four types of fibers (with significant differences in surface properties, flexibility, and particle size distributions) - 16 total combinations as a starting point. Our research program will pursue three (3) objectives:Objective 1: Determine the effects of starch and insoluble fiber on the physicochemical and mechanical behaviors of starch polymer matrices.Hypothesis: Certain properties of starch (thermal and rheological) and insoluble fiber (surface characteristics, flexibility and particle size distributions) will significantly correlate to the final physicochemical and mechanical properties of the ingredient matrix and final product after processing. Objective 2: Determine the impact of extrusion-processing parameters on starch-fiber interactions during extrusion and in the final extruded product.Hypothesis: Changing the amounts of mechanical and thermal energy imparted to the extruded materials will significantly impact the expanded cellular structure by causing changes in starch properties, fiber distribution, and binding in the starch matrix.Objective 3: Evaluate the sensory attributes of the products produced with different starches and fibers under varying processing conditions.Hypothesis: Reducing the disruption of the starch matrix will yield products with sensory texture attributes that more similarly align with those produced from refined grain. Sensory attributes will be related to the physical- and mechanical measurements gained in Objectives 1 and 2.
Project Methods
In Phase I, we will determine the physicochemical characterization of 4 different fibers, 4 different starches and the mixtures of the starches and fibers (Table 1). The fibers are selected for their significant differences in size distribution, surface roughness, and firmness. These criteria were selected based on our learnings from the preliminary data. Studies on fiber characterization will be published in peer-reviewed journals to address the current lack of such data in the literature. The physicochemical properties of four selected starches (native and waxy corn, native and waxy wheat) will also be determined. These starches were selected because of the known significant differences in their characteristics and also because they are the most common starches used in extruded foods.We plan to determine the impact of individual material flow, deformation and friction of defined mixtures of selected starches and fibers using rheometry and tribometry on these selected fibers (Table 1). In addition, these mixtures will be evaluated using 2-dimensional NMR to measure the molecular interactions between fiber and starch (Table 2).Table 1. Experimental plan for Phase I characterization of the fiber-starch mixtures.MaterialFactorsLevelsMixture AnalysisStarchWaxy CornFiber Levels0 % w/w5 " "10 " "20 " "30 " "Rheology StudiesTribology StudiesNMR StudiesNMR Model StudiesRegular Corn50% Amylose Corn (high)70% Amylose Corn (high)FiberWhole Apple Pomace FiberMoisture Levels15 % w.b.20 " "25 " "30 " "80 " "Whole Oat Hull FiberPure Cellulose FiberWheat Bran FiberFiber levels of 0, 5, 10, 20, and 30% were chosen because they represent a negative control (0%), a positive control (30%) and three fiber levels that are representative of the amounts found in the majority of whole-grain food products. Moisture levels of 15, 20, 25, and 30% were chosen to represent the moisture levels used in most extruded cereals and snacks; one control moisture level (80%, or excess moisture) will also be used. The results from the rheology, tribology, and NMR studies will be analyzed to determine which model systems to use for thorough molecular investigation. Further, model systems will be developed (for NMR studies) that simulate starch/fiber interaction behaviors but are chemically simple and easier to analyze. These model systems will help explain the molecular interactions between the various starches and fibers (Table 1).In Phase II, we will evaluate the effects of extrusion processing on starch and fiber mixtures as shown in Table 2. Extrusion conditions were selected to represent the processing conditions used by the food industry to produce the majority of direct-expanded cereals and snacks. We will characterize the extruded products in terms of physicochemical, mechanical and rheological properties, and quantify starch-fiber interactions.Table 2. Experimental plan for Phase II extrusion studies.MaterialFactorLevelsExtrudate AnalysisStarchWaxy CornFiber levelsMoisture levelsScrew profilesScrew speedsDie diameterFeed ratesBarreltemperatures0, 5, 10, 20 and 30 (% w/w)15, 20, 25, and 30% w.b.3 different shear profiles50, 150, and 250 rpm2, 3, and 4 mm (round die)2, 4, and 6 kg/hr100, 125, and 150oCPhysical propertiesWater absorption and solubility propertiesRheology and TribologyFTIR StudiesMicroscopic characterizationRegular Corn50% Amylose Corn70% Amylose CornFiberWhole Apple PomaceWhole Oat HullPure CelluloseWheat BranFinally, in Phase III, we will evaluate the sensory attributes of the extruded products and relate them back to the physicochemical and mechanical properties of both the extruded products and the unprocessed starch, and fiber mixtures (Table2). A summary of the analytical techniques used in this study is provided on the next pages, after the timeline of work.From Table2, it is clear that we will obtain a large number of extruded samples under different operating conditions. Since it will be impractical to evaluate all of the extruded samples via sensory testing, samples will be screened by utilizing the analytical data collected, to eliminate the samples that do not expand at all or have no open cellular structure. Instrumental data will also be used to aid this screening process. Only the screened samples will be subjected to thorough sensory analysis. Sensory data will be analyzed in conjunction with previously collected data to determine relationships among sensory attributes, physicochemical properties, and mechanical behaviors.From this experimental work, we plan to publish 12 peer-reviewed journal articles. This will add significant and valuable information to the literature. In addition, at least three oral or poster presentations will be conducted at national and international conferences.

Progress 02/15/18 to 02/14/24

Outputs
Target Audience:The target audience(s) reached are food processors producing any kind of high fiber foods or intending to produce high fiber foods, including snacks, breakfast cereals, and others. Additionally, food ingredient manufacturers, who process high fiber ingredients. Changes/Problems:The biggest challenge we faced while conducting the work for this grant was the COVID-19 pandemic and the related governor's order. We were forced to close down the laboratory completely for about twelve weeks. Afterward, we slowly ramped up the work. However, extrusion work and the use of shared laboratory facilities came with a delay, really slowing down the practical process in the laboratory. Besides that, sensory testing had to be conducted as a home-use test as a result of the pandemic. Another organizational problem was the departure of one of the Co-PIs, Dr. Helen Joyner, who was responsible for the rheology and tribology equipment; hence, making it very difficult for us to conduct some of the proposed work. Further, Dr. Huber also moved to BYU in Rexberg, ID. However, we were able to work with Dr. Huber, who provided valuable input with his expertise in fiber and carbohydrate chemistry. Regarding the work conducted, we realized that the complexity of the biopolymers of interest, namely starch and fiber, makes specific analyses difficult. Although we were aware of this fact when writing the proposal and therefore included the analysis of model compounds, we were forced to focus on the process-induced changes by comparing the raw and the extruded material. For the same reason, certain analyses had to be eliminated from the initially proposed experimental designs. To overcome the challenges that come with the complexity of the molecules, we analyzed maltose and cellobiose as model compounds. The NMR analysis of these smaller molecules came with difficulties. The huge difference in size between the smallest model compounds (maltose and cellobiose) and the biopolymers (starch and cellulose) provoke very different behaviors. Increasing the size of the model compounds would help translating the results more easily to the behavior of the bigger compounds but would further complicate the NMR spectra to an extent that would not allow us to come to satisfying conclusions. Therefore, we have changed our approach by analyzing the molecular interactions between starch and cellulose in a "simulated extrusion process" using a pressure vessel. The developed setup allowed us to analyze materials that we were able to obtain in small quantities only and that were further synthesized using chemicals that we did not want to get in touch with a food grade extruder. We specifically methylated starch to eliminate (some of) the hydroxyl groups, subsequently disabling hydrogen bonds from occurring. We compared this methylated starch with un-methylated starch for their expansion behavior in the newly developed setup. Additionally, we identified that the insoluble fiber generally disrupts the continuous phase of the molten starch, leading to reduced expansion behavior. Soluble fibers, such as pectin or tamarind seed gum, may help to maintain the continuous phase and the viscosity of the melt during extrusion, favoring the expansion, and have therefore been added to our studies. What opportunities for training and professional development has the project provided?The project offered great opportunities for students to learn the principles of extrusion processing. The great variety of the materials made students understand the effect of the raw material on the process and the changes in the material that come with the processing. The use of different processing parameters throughout the studies has helped students learn how to operate an extruder, successfully select the right conditions during a smooth run, and in critical situations in which immediate action is required. Multiple students are able to operate the twin-screw extruder in our laboratory themselves - a very valuable knowledge for their professional future. Characterization of raw material and extrudates enabled students, graduates as well as undergraduates, to learn diverse analytical techniques, including the measurement of the pasting properties using a ViscoQuick, rheology measurements, Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Confocal Laser Scanning Microscope (CLSM), Fourier-Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and solution as well as solid-state Nuclear Magnetic Resonance (NMR) spectroscopy. These trendsetting methods help students find solutions for understanding molecular interactions in different food ingredients and products during extrusion processing and other operations. Being able to understand such interactions is critical for the development of new products. Besides that, one Ph.D. student gained valuable engineering and chemical synthesis knowledge. Additionally, several students were able to gain experience in sensory methodologies, both trained panel and consumer studies. Additionally, five students (four Ph.D. and one Master's student) were able to experience and network at different conferences while presenting their work on this project. Along with these, 5 undergraduate students were able to gain valuable experience working on the extrusion processing technology. How have the results been disseminated to communities of interest?The results have been disseminated to the scientific community through scientific publications (9 published + 1 in review), dissertation and thesis publications (3 Ph.D. dissertations + 1 Master thesis), and poster presentations (8). Besides that, part of our results were shared with industry representatives during our annual extrusion workshop at Washington State University, as well as through the extension work conducted in our laboratory. Our main findings were also shared with PepsiCo and Fruit Smart, Inc. companies. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The effect of cellulose, cellulose derivatives, specifically nanocrystals and microcrystalline cellulose, tamarind gum, untreated and pretreated fruit pomaces, low and high methoxyl pectin, as well as sugars on direct expanded corn starch extrudates has been evaluated in different extrusion studies. Due to the difficulties of collecting samples at different stages of the process without any changes in the structure of the samples, we have additionally tried to tackle the question of interest from a different perspective: (1) We evaluated the feasibility of analyzing smaller, less complex model compounds using solution 1H nuclear magnetic resonance (NMR) spectroscopy for understanding the molecular interactions between the bigger biopolymers during extrusion processing; and (2) We developed a system that allows for a simulated expansion process, allowing us to use materials, such as methylated starch, that are not available in large quantities, and which should not get into touch with a food-grade extruder. The main findings are as follows: The inclusion of fiber reduces the size of the created air cells and leads to a more uniform structure. Hence, fibers can be used as nucleating agents. However, the cellular structure possessed thinner and more ruptured cell walls. Fiber, specifically cellulose, does not undergo phase changes or molecular changes into a paste; hence, enabling cellulose to weaken the paste structure and disrupt the starch matrix. Cellulose significantly affects the thermal, pasting, and rheological properties of corn starch. The effect of cellulose is dependent on the amylose content of the specific starch. Cellulose is unevenly distributed throughout the starch matrix as it tends to aggregate under heat, shear, and low moisture conditions as given during extrusion processing. The occurrence of a phase separation between starch and fiber may explain physicochemical properties. Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy suggest that starch and fiber interact mainly through hydrogen bonding during extrusion processing; covalent bonds seem not to be formed. Cellulose may specifically disrupt the intermolecular hydrogen bonding of starch during the expansion phenomenon. Sugars can help to increase the expansion of starch-cellulose extrudates and may further help to reduce the phase separation between starch and cellulose. The inclusion of high methoxyl pectin has a positive effect on starch-cellulose extrudates. It improves the extensibility of the starch-cellulose matrix and reduces the phase separation between starch and fiber, favoring bubble growth and expansion of the extrudates. High methoxyl pectin maintained expansion characteristics of starch-cellulose extrudates compared to low methoxyl pectin while simultaneously increasing the total dietary fiber content. Inclusion of tamarind gum, a hydrocolloid, enhances direct expansion characteristics under certain conditions by modifying the viscoelastic and thermal characteristics of corn starch. Crystallinity seems to affect the expansion ratio. The high crystallinity of cellulose seems to have a negative effect on the expansion. Reassociation might be influenced by fiber. Modification or pretreatment of fiber affects expanded products. Pretreatment of apple pomace with hydrochloric acid can enhance the expansion under certain conditions. The inclusion of cellulose nanocrystals is beneficial compared to the inclusion of microcrystalline cellulose. Consumer liking of extruded puffed snacks differs significantly based on the type and percentage of pomace added. Sensory analysis showed that the inclusion of up to 15-20% apple pomace into corn starch extrudates increased consumer liking. However, consumer liking of corn starch extrudates containing cranberry pomace only enhance up to an inclusion level of 5-10%. When including higher levels, acceptance decreased due to differences in texture and taste, including denser characteristics, increased toothpack, astringency, and bitterness. The analysis of model compounds is unfeasible for understanding the molecular interactions between starch and fiber during extrusion processing. Starch can be expanded successfully in a pressure vessel system. Methylated starch, without and with the inclusion of cellulose, behaves significantly different than un-methylated starch. Potential reasons are the elimination of hydrogen bonds but may further be a result of an increased viscosity.

Publications

  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Dey D, Gu BJ, Ek P, Rangira I, Saunders SR, Kiszonas AM, and Ganjyal GM. 2021. Apple pomace pretreated with hydrochloric acid exhibited better adherence with the corn starch during extrusion expansion. Carbohydrate Polymer Technologies and Applications, 2, 100089.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Ek P, Gu BJ, Saunders SR, Huber K, and Ganjyal GM. 2021. Exploration of physicochemical properties and molecular interactions between cellulose and high-amylose cornstarch during extrusion processing. Current Research in Food Science. 4(June), 588-597.
  • Type: Journal Articles Status: Accepted Year Published: 2020 Citation: Xie F, Gu BJ, Saunders SR, and Ganjyal GM*. 2020. High methoxyl pectin enhances the expansion characteristics of the cornstarch relative to the low methoxyl pectin. Food Hydrocolloids. 110(2021): 106131.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Dey D, Richter JK, Ek P, Gu BJ, Ganjyal GM. 2021. A review of food processing by-products utilization in extrusion processing. Frontiers in Sustainable Food Systems, 4, 304.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: " Richter JK, Gu BJ, Ek P, Dey D, Saunders SR, and Ganjyal GM. 2022. Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded products. Journal of Food Science. 2222: 1-15. https://doi.org/10.1111/1750-3841.16240.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Wagner C, Richter JK, Dey D, Finne S, and Ganjyal GM. 2023. Impact of tamarind seed gum on the viscosity behavior, thermal properties, and extrusion characteristics of native corn starch. Journal of Food Science. 115. https://doi.org/10.1111/1750-3841.16513.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Dey D, Gu BJ, Ek P, Ross CF, Saunders SR, and Ganjyal GM. 2023. Influences of modified fiber inclusion with varying particle size on corn starch-based extrudate expansion. Journal of Food Science. https://doi.org/10.1111/1750-3841.16432.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Ek P, Gu BJ, Richter JK, Dey D, Saunder SR, Ganjyal GM. 2023. High methoxyl pectin can improve the extrusion characteristics and increase the dietary fiber content of starch-cellulose extrudates. Journal of Food Science. https://doi.org/10.1111/1750-3841.16742.
  • Type: Journal Articles Status: Published Year Published: 2024 Citation: Ek P, Gu BJ, Dey D, Richter KJ, Saunders SR, Ganjyal GM. 2024. Cellulose interferes with the transformation of cornstarch during extrusion processing. ACS Food Science & Technology. (In Press). https://doi.org/10.1021/acsfoodscitech.3c00578.
  • Type: Journal Articles Status: Under Review Year Published: 2024 Citation: Richter JK, Saunders SR, Ikuse M, Finnie SM, Ganjyal GM. 2024. Development of a novel pressure vessel system for the simulation of starch expansion  Methylated and regular waxy corn starch behave significantly different with and without cellulose inclusion. Starch  St�rke. (In Review).
  • Type: Journal Articles Status: Other Year Published: 2024 Citation: Kloepfer I, Ganjyal GM, Gu BJ, Ek P, Ross CF. 2024. Trained panel and consumer evaluation of corn extruded puff snacks containing apple and cranberry fiber. Journal of Food Science. (In Prepration).
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Richter JK, Gu BJ, Ek P, Dey D, Saunders SR, & Ganjyal GM. 2022. Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded extrudates. Conference of Food Engineering (CoFE), 2022.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Kloepfer I, Ganjyal GM, Gu BJ, Ek P, Ross CF. 2022. Trained panel and consumer evaluation of corn extruded puff snacks with apple and cranberry fiber. IFT First Annual Event and Expo, Chicago, IL, United States.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: " Wagner CE, Richter JK, Dey D, Ganjyal GM. 2022. Tamarind seed gum improves the extrusion expansion characteristics of native corn starch at low inclusion levels. IFT First Annual Event and Expo, Chicago, IL, United States.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Dey D, Gu BJ, and Ganjyal. 2021. Influence of different sugars on the expansion characteristics of corn starch extrudates. Institute of Food Technologists Annual Meeting. July 2021.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Dey D, Ek P, Gu BJ, and Ganjyal GM. 2021. Rheological characterization of microcrystalline cellulose-corn starch blends and its impact on the expansion of extrudates. Cereals and Grans Association Annual Meeting 2021.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Dey D, Gu B, and Ganjyal GM. 2020. Exploring the formation of molecular bonds between starch and fiber during production of cereal-based puffed snacks using infrared spectroscopy. Academic Showcase, Washington State University, 2020 April, Washington, U.S.A.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Dey D, Gu B, and Ganjyal GM. 2020. Quantification of starch and fiber interactions in direct-expanded snacks manufactured using corn starch and acid-treated apple pomace using FTIR spectroscopy. Cereals and Grains Association Annual Meeting 2020. 10-25 October 2020.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Ek P, Gu B, and Ganjyal GM. 2019. Understanding the physical and molecular changes in the mixtures of cellulose and corn starch during extrusion processing using Fourier Transform- Infrared Spectroscopy (FTIR). Cereals and Grains Association annual meeting 2019. 03-05 November 2019, Denver, Colorado, U.S.


Progress 02/15/22 to 02/14/23

Outputs
Target Audience:The target audience(s) reached are food processors producing any kind of high-fiber foods or intending to produce high-fiber foods, including snacks, breakfast cereals, and others. Additionally, food ingredient manufacturers, who process high-fiber ingredients are addressed. Changes/Problems:As mentioned previously, the NMR analysis of model compounds came with difficulties. The size differences between the biopolymers and their model compounds come with very significant differences in characteristics that make the very small model compounds not suitable for our approach. Using bigger molecules, however, complicates the NMR spectra greatly, and does not allow us to come to any conclusion. We have therefore changed our approach and aim for understanding the interaction between the biopolymers starch and fiber in a "simulated extrusion process". Set up of the required equipment for this approach has come with delays due to supply chain issues. We are currently working on methylating starch. The published methodology is described on a much smaller scale than needed for our experiment. Besides that, we do not obtain the yield given in the published paper. We are still trying to figure out how to improve this relatively simple microwave method as other methylation pathways are much more complicated and time-consuming. Unfortunately, it takes more time than expected. What opportunities for training and professional development has the project provided?As described in previous reports, the project offered great opportunities for students to learn the principles of extrusion processing. The great variety of processed materials made students understand the effect of the raw material. The use of different processing parameters throughout the studies has helped students learn how to operate an extruder and how to successfully select the right conditions during a smooth run but also in critical situations in which immediate action is required. Multiple students are able to operate the twin-screw extruder in our laboratory themselves; which is very valuable knowledge for their professional future. Characterization of raw material and extrudates enabled students, graduates as well as undergraduates, to learn diverse analytical techniques, including the measurement of the pasting properties using a ViscoQuick, rheology measurements, Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Confocal Laser Scanning Microscope (CLSM), Fourier-Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), and solution as well as solid-state Nuclear Magnetic Resonance (NMR) spectroscopy. The familiarization with these techniques did not only help students understand specific principles but further made them understand that many different techniques are generally required to answer one question or solve a problem. Besides that, our approach change allowed one Ph.D. student to gain valuable engineering and chemical synthesis knowledge. Additionally, several students were able to gain experience in sensory methodologies, both trained panel and consumer studies. Three students (two Ph.D. and one Master's student) were able to present their work on this project at two different conferences. How have the results been disseminated to communities of interest?The results have been disseminated to the scientific community through scientific publications, dissertation publications, and oral and poster presentations. During this reporting period, the study covering the effect of blueberry and cranberry pomace on native and waxy corn starch has been published as an original research article in the Journal of Food Science and has further been presented in a poster presentation at the Conference of Food Engineering (CoFE), 2022. The effect of Tamarind seed gum on corn starch extrudates as well as the trained panel and consumer evaluation of snack products fortified with apple and cranberry pomace has been presented as posters at the Institute of Food Technologists FIRST Annual Conference, 2022. The manuscript for the former one has been submitted and is in its second review round right now. Debomitra Dey, a previous Ph.D. student, and Ivy Kloepfer, a previous Master's student, presented their results in this research project during their successful Ph.D. and Master's defense as well as in their dissertation. What do you plan to do during the next reporting period to accomplish the goals?During the next and last reporting period, the ongoing studies will be completed, and the manuscripts will be submitted to journals. We are specifically planning: We are planning on conducting a full experimental design on the simulated expansion process using the designed set-up of the pressure vessel. As for now, we are trying out different methods for methylating starch. Once we have confirmed a protocol, we will work on scaling it up, and "synthesize" the needed amount. We will then be processing different material combinations. The raw material will include waxy corn starch in its native form and its methylated form, as well as cellulose as the fiber component. The expansion of the material will be measured through density measurement with ethanol as a displacement medium. Further analysis will include the evaluation of the hydration properties (water solubility and water absorption index) as well as imaging with a scanning electron microscope (SME). We will continue to disseminate the results obtained through peer-reviewed journals and conferences.

Impacts
What was accomplished under these goals? Following the work conducted in the last report period, the study on the effects of blueberry and cranberry pomace on native and waxy corn starch extrudates has been published in the Journal of Food Science. A study on the effect of tamarind seed gum (TSG), a cold-water-soluble hydrocolloid gum, has been conducted, and a manuscript has been submitted to the Journal of Food Science. It is in the second round of review right now. The main findings included: Tamarind gum effectively modifies the viscoelastic and thermal characteristics of corn starch in a way that enhances the direct expansion characteristics. The effect is more beneficial at lower gum inclusion levels since higher levels result in reduced capabilities to translate shear from the extruder into useful transformations of the starch polymers. Pasting properties indicated that TSG inclusion increases viscosity but also makes the starch-gum paste more susceptible to permanent shear degradation. Thermal analysis indicated that TSG inclusion narrowed the melting endotherms and lowered the energy required for melting at higher inclusion levels. Extruder back pressure, motor torque, and specific mechanical energy (SME) decreased with increasing TSG levels as TSG effectively lowered the melt viscosity at high shear rates. Small inclusions of TSG can improve the expansion properties of starch, while larger inclusions result in a lubrication effect that mitigates the shear-induced depolymerization of starch. The work on the simulated expansion process using a pressure vessel is ongoing. We were able to successfully expand waxy corn starch, and finalize the optimal conditions. Sensory work was completed with the following results - Consumer liking of the extruded puffed snacks differed significantly based on the pomace percentage. Among the apple pomace samples, consumers indicated the highest overall acceptance for samples containing 5% and 15% apple pomace, products characterized by their salted caramel aroma and buttery flavor attributes. Consumers showed the lowest overall acceptance for samples containing 25% apple pomace replacement and control, defined by sour and salty attributes, respectively. Among the cranberry extruded puffed snacks, consumers showed the highest acceptance for control and the sample containing 5% cranberry pomace replacement, characterized by moisture absorption and flavor attributes. Consumers had the lowest overall acceptance for samples containing 20% and 25% cranberry pomace replacement, defined by their toothpack, astringency, and bitter attributes. This study determined that in an extruded puffed snack product, the replacement of corn flour with apple pomace (at 15% replacement) or cranberry pomace (at 10% replacement) resulted in products that were still acceptable to consumers. Ultimately, this research may lead to high quality and nutritious extruded snack products.

Publications

  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Wagner C , Richter JK , Dey D , Finne S, and Ganjyal GM*. 2023. Impact of tamarind seed gum on the viscosity behavior, thermal properties, and extrusion characteristics of native corn starch. Journal of Food Science. 115. https://doi.org/10.1111/1750-3841.16513.
  • Type: Journal Articles Status: Published Year Published: 2023 Citation: Dey D , Gu BJ , Ek P , Ross CF, Saunders SR, and Ganjyal GM*. 2023. Influences of modified fiber inclusion with varying particle size on corn starch-based extrudate expansion. Journal of Food Science. https://doi.org/10.1111/1750-3841.16432.
  • Type: Journal Articles Status: Published Year Published: 2022 Citation: Richter JK , Gu BJ , Ek P , Dey D , Saunders SR, and Ganjyal GM*. 2022. Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded products. Journal of Food Science. 2222: 1-15. https://doi.org/10.1111/1750-3841.16240.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: Richter, J. K., Gu, B.-J., Ek, P., Dey, D., Saunders, S. R., & Ganjyal, G. M. 2022. Potential interactions between starch and fruit pomace may impact the expansion ratio of direct expanded extrudates. Conference of Food Engineering (CoFE), 2022.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: " Wagner, C.E., Richter, J.K., Dey, D., Ganjyal, G.M. (2022, July 10th-13th) Tamarind seed gum improves the extrusion expansion characteristics of native corn starch at low inclusion levels. IFT First Annual Event and Expo, Chicago, IL, United States.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2022 Citation: " Kloepfer, I., Ganjyal, G.M., Gu, B.-J., Ek, P., Ross, C.F. (2022, July 10th-13th) Trained panel and consumer evaluation of corn extruded puff snacks with apple and cranberry fiber. IFT First Annual Event and Expo, Chicago, IL, United States.


Progress 02/15/21 to 02/14/22

Outputs
Target Audience:Target audiencesinclude the food industry, including the ingredient manufacturers and extruded product manufacturers such as cereals, snacks, and others. The audience also included other researchers working on the topics of extrusion and carbohydrates. Changes/Problems: As described previously, the difficulty or infeasibility of drawing samples at different stages during extrusion and the impossibility of complete simulation of the conditions inside the extruder brought us to focus on the process-induced changes between the raw material and the extrudates rather than on the characteristics of the material during the process. In current studies, we have analyzed the raw materials, the raw blends, as well as the final extrudates. The comparison of raw and final extrudates has helped us to understand the molecular interactions that could occur in the extruder. In addition to FTIR, XRD and NMR techniques were utilized to explain the molecular interactions of starch and fiber. The analysis of model compounds with NMR came with difficulties. The huge difference in size between the smallest model compounds (maltose and cellobiose) and the biopolymers (starch and cellulose) cause them to have very different behavior. Therefore, we would need to increase the size of the model compounds significantly to obtain results that can be transferred to starch and fibers during extrusion. Unfortunately, increasing the size of the model compounds results in very complicated spectra that do not allow us to make any conclusions. Hence, we are changing our approach by aiming to analyze the interaction between starch and fiber in a "simulated extrusion process" using a pressure vessel. The size of the molecules, as well as the process, is closer to the extrusion phenomenon of interest. Making changes and modifications to (dextrinized) starch and the present conditions that we would not be able to do for the extrusion process itself will allow us to get a more fundamental explanation of the presence and importance of interactions, specifically hydrogen bonds. Moreover, we have identified that the insoluble fibers generally disrupt the continuous phase of molten starch, leading to the reduced expansion of extrudates. Therefore, soluble fibers such as different types of pectin tamarind seed gum have been added to our research studies because the soluble fibers may help to maintain the continuous phase of molten starch and the viscosity of melt during extrusion, which then favor the expansion of the extrudates. Also, adding soluble fibers will still help to maintain the final goal of producing high fiber extrudates. For rheological studies, due to some limits in simulating the extrusion conditions with our current rheometer, the rheological studies of the starch-fiber pastes have been conducted at the atmospheric conditions (atmospheric pressure and ambient temperature). Despite of the changes, the results of these studies have been helped to explain the effects of cellulose and other fibers on the flow behavior and viscoelastic properties of starch pastes which we can use to explain the properties of raw blends and their extrusion characteristics. For the sensory evaluation study, a major challenge with completing this research has been COVID-19 and the associated temporary suspension of sensory testing in 2020. While still adhering to COVID-19 precautions, we were able to resume sensory testing in 2021 but had to make a number of modifications. Our consumer testing needed to be conducted as a home-use test, and our trained panel research needed to be performed under strict COVID-19 precautions. Making this pivot in our research methodologies put us a little behind schedule, and as such, data analysis is still underway. While the sensory data have been analyzed, the associated physical data still need to be analyzed and included in the PLS results. What opportunities for training and professional development has the project provided?Objective 1 provided great insights into extrusion processing for students. The students learned and understood the fundamentals of the processed materials and their changes during extrusion processing. This learning outcome is essential for students to effectively choose the material for any extrusion experiment. The studies on raw material characterization further strengthened the students' understanding of the thermal and functional properties of pomaces from different sources. The analytical techniques included Micro-Visco-Amylograph (MVAG), rheological measurement techniques for flow behavior and viscoelastic properties, and Differential Scanning Calorimetry (DSC). Rheological studies on the blends of corn starch and fiber have helped in explaining the physicochemical interactions during extrusion processing. The students have operated the equipment themselves; hence, they learned the fundamentals of using the techniques and equipment for their future research and professional works. Objective 2 again provided great insights into extrusion processing for students, especially the operation of a twin-screw extruder. This objective aimed to understand the influence of independent parameters. The learning outcomes are essential for the students to successfully operate the extruder and to improve the settings. In addition, the analysis of the interaction during extrusion processing requires the students to explore different analysis techniques, including microscopic analysis using Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM), and various spectroscopic techniques, such as Fourier-Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), and Nuclear Magnetic Resonance (NMR) spectroscopy. These methods have helped the students to solve many questions regarding the molecular interactions of different food ingredients/components not only during extrusion processing but also during other operations. Being able to understand such interactions is critical for the development of new food products. Objective 3: this research has provided training and professional development to several graduate students. One graduate student, Ivy Kloepfer, has been the primary researcher and has gained experience in experimental design, sensory methodologies, chemical and physical analyses, and extrusion technologies. Also, given the extensiveness of the sensory evaluation testing (both trained panel and consumer studies), this research allowed three other graduate students to gain practical experience in conducting sensory studies. How have the results been disseminated to communities of interest?The results have been disseminated to the scientific community through scientific publications, dissertation publications, and oral and poster presentations. Two original research articles have been published in Carbohydrate Polymer Technologies and Current Research in Food Science (Dey et al., 2021 and Ek et al., 2021). An oral and a poster presentation were presented at the annual meetings of the Institute of Food Technologist, 2021, and Cereals and Grains, 2021. In addition, a Ph.D. student (Ms. Pichmony Ek) presented the results of this research project during her Ph.D. defense and in her dissertation. What do you plan to do during the next reporting period to accomplish the goals?During the next reporting period, the ongoing studies will be completed, and their manuscripts will be submitted to journals. Moreover, a few new studies will be conducted with the complete data collections. The specific plans of each objective are described below. Objective 1: The studies of the effects of pectin, sugars, and fibers from fruits (cranberry and blueberry) on the extrusion characteristics of starches; the effects of cellulose on the rheological properties of starches have their data collections completed. Thus, the plan is to complete the manuscripts and get them published during the next reporting period. Due to difficulties when analyzing model compounds with NMR, we are planning to use a pressure vessel to simulate the expansion phenomenon during extrusion with compounds bigger than the model compounds we used so far but smaller than the biopolymers starch and fiber. Moreover, a study on understanding the role of a cross-linking agent in mitigating phase separation in starch and fiber blends will be conducted. Enhancing the pasting, thermal, and rheological properties of starch-Microcrystalline cellulose (MCC) blends by using NaOH as a co-solvent. Objective 2: The studies of the effects of chemically derived cellulose fibers (cellulose nanocrystal - CNC, and microcrystalline cellulose - MCC), pectin types, sugars and fibers from fruits (cranberry and blueberry) on the extrusion characteristics of starches, have their data collections completed. Thus, the plan is to complete the manuscripts and get them published during the next reporting period. A study of the presence and importance of hydrogen bonds during the expansion process using modified starches in a pressure vessel for a "simulated extrusion process" will be conducted. A study of the presence and importance of hydrogen bonds during the expansion process by changing the pH of the starch-based blends and melt will be conducted. A study on the effects of tamarind seed gum (TSG) on starch expansion during extrusion processing will be conducted because (TSG) has not been explored for extrusion application at all in the literature, and has been identified as a novel gum to use in extrusion due to its reported excellent heat, pH, and shear stability properties. Powdered TSG is commonly used as a thickening, gelling and stabilizing agent in processed foods in Asia (especially Japan), but has seen limited adoption in North America. Objective 3: we have completed the data collection. The data analysis is still ongoing, with the expected completion of this analysis being February 2022. The graduate student funded by this research project, Ivy Kloepfer, is currently writing up this research for her MS thesis, with her expected graduation being Spring 2022. Ivy is also working toward submitting this research to the Journal of Food Science and for presentation at the Institute of Food Technologists 2022 Annual Meeting.

Impacts
What was accomplished under these goals? Objective 1: Determine the effects of starch and insoluble fiber on the physicochemical and mechanical behaviors of starch polymer matrices. Following the results and main findings in the previous year, the studies on the effects of chemically modified apple pomace and the exploration of high-amylose starch and cellulose have been published (Dey et al., 2021 and Ek et al., 2021). The manuscript about the transformation of starch-cellulose melt has been submitted to Carbohydrate Polymers (status: under revision). Moreover, the manuscripts about the effects of high and low methoxyl pectin on the expansion of starch-cellulose extrudates; inclusion of sugars on extrusion of corn starch-MCC extrudates; the effects of fibers from fruits (blueberry and cranberry pomace) on starches; the effects of cellulose on the rheological properties of starches are under preparation. The study of interactions of starch and fiber using the model compounds with NMR was conducted, and the results led us to another study using the pressure vessel to simulate the extrusion conditions. Key findings of these studies are as the following: The inclusions of high methoxyl pectin (HMP) and low methoxyl pectin (LMP) showed significantly different impacts on cornstarch cellulose extrudates. HMP improved the peak viscosity (629.7±8.1 to 754.7±80.1 mPa.s) and maintained the final viscosity compared to the control (starch-cellulose mixture alone), unlike LMP. Adding HMP to the mixtures improved the extensibility of the melt, favoring the bubble growth and expansion of the extrudates. The inclusion of glucose and fructose in corn starch-microcrystalline cellulose (MCC) blends showed a significantly different impact on the flow profile of the blends. The corn starch blends had the highest viscosity and shear stress. The shear stress reduced on the inclusion of MCC, glucose, and fructose. The decrease in shear stress was due to the lack of entanglements formed because of the starch dilution in the system. Fructose showed higher shear stress than glucose, and this behavior was also observed when they were blended with corn starch and MCC. Cellulose significantly affected the thermal, pasting, and rheological properties of corn starches with different amylose content. The pastes of the mixtures had pseudo-plastic and shear-thinning behaviors. Concentrations >5% of cellulose disrupted the continuous network of starch molecules and weakened the structure of starch pastes, but the degree of this disruption differed based upon the amylose content of corn starch. Waxy corn starch could hold cellulose particles in its matrix better compared to normal starch, but it is more susceptible to breakdown by mechanical shear. Objective 2: Determine the impact of extrusion-processing parameters on starch-fiber interactions during extrusion and in the final extruded product. Following the results and main findings in the previous year, the studies on the effects of chemically modified apple pomace and the exploration of high-amylose starch and cellulose have been published (Dey et al., 2021 and Ek et al., 2021). Moreover, the manuscripts on the effects of high and low methoxyl pectin on the expansion of starch-cellulose extrudates; inclusion of sugars on extrusion of corn starch-MCC extrudates; the effects of modified fiber - cellulose nanocrystal (CNC) and microcrystalline cellulose (MCC) inclusion on the expansion of extrudates; the effects of blueberry and cranberry pomace on the expansion of starches, are under preparation. One oral presentation and poster presentation by Dey et al. (2021a, 2021b) were showcased in the Institute of Food Technologists and Cereals and Grains 2021 annual meeting, respectively. Key findings of these studies are as the following: The effects of cellulose on the expansion of starch-based extrudates were mainly due to the physical incompatibility of starch and cellulose because cellulose was confirmed to be resistant to breakdown and did not go through any phase change under the conditions studied. Molecular interaction between starch and fiber after extrusion was via hydrogen bonding. Cellulose could interfere with starch chain reassociation through intermolecular hydrogen bonding during the expansion process. The reduction in the expansion with increasing cellulose content could be due to two main reasons. The first reason was the phase separation of cellulose (small particles) and starch melt (continuous phase), which interfered with the reassociation of starch molecules during the expansion. Another cause of expansion reduction was the uneven distribution of the cellulose within the starch matrix because cellulose particles tended to aggregate during the extrusion processing. HMP maintained the expansion characteristic of starch-cellulose extrudates and improved its total dietary fiber content relative to LMP. FTIR data suggested that there could be intermolecular interactions between starch, cellulose, and pectin, but the nature of these interactions needs further investigation. The earlier study by Dey et al. (2021) reported that modified fiber inclusion during extrusion of corn starch at lower inclusion could result in improving the expansion ratio of extrudates. This could be attributed to intermolecular interactions between starch and modified fiber. To expand the scope of this study, we selected two chemically derived cellulose fiber - cellulose nanocrystal (CNC) and microcrystalline cellulose (MCC). Each of these fibers was included at 1, 3, 5, 10% (w/w) with corn starch, and their individual impact on the expansion of extrudates was investigated. The CNC extrudates at 10% (w/w) inclusion were found to have higher ER due to their lower crystallinity and particle size. In contrast, MCC had good expansion up to 5% (w/w) inclusion and failed to have good expansion at 10% (w/w) inclusion. This study indicated that the low crystallinity of CNC favored the high expansion of extrudates. The manuscript for this study is currently under preparation. Two sugars - glucose and fructose were selected and incorporated into starch and MCC blends. The extrudates with fructose inclusion in corn starch-MCC blends had higher expansion compared to glucose inclusion in the blends. One of the reasons for this result is the possibility of phase separation between the ingredients. The phase separation between corn starch-MCC could be mitigated by fructose inclusion, and this was supported by the rheological studies. The phase separation in the extrudates was observed by confocal laser scanning microscopy (CLSM) imaging. MCC was observed to form aggregates on the extrudates structure. The data collection and analysis are completed for this study, and the manuscript is under preparation. Objective 3: Evaluate the sensory attributes of the products produced with different starches and fibers under varying processing conditions. Apple and cranberry pomace were identified as sources of pomace from the previous objectives. A sensory study (trained panel profiling and consumer assessment) of corn-based extruded products incorporated with apple and cranberry pomace was conducted. In brief, formulations for the extruded products included the replacement of cornflour at levels of 0 (control), 5, 15, 20, and 25% (w/w). For future sample reference, the name of the pomace is listed first, followed by the replacement value. All products were seasoned with salted caramel flavoring. A total of 11 products were prepared. This study was reviewed and approved for human subject participation by the Washington State University Institutional Review Board (IRB #18786). Informed consent was obtained from each subject prior to their participation in the trained sensory panel or the consumer acceptance testing. The data collection was completed and a manuscript to be submitted to the Journal of Food Science is under preparation.

Publications

  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Dey D, Gu BJ, Ek P, Rangira I, Saunders SR, Kiszonas AM, and Ganjyal GM. 2021. Apple pomace pretreated with hydrochloric acid exhibited better adherence with the corn starch during extrusion expansion. Carbohydrate Polymer Technologies and Applications, 2, 100089.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Ek P, Gu BJ, Saunders SR, Huber K and Ganjyal GM. 2021. Exploration of physicochemical properties and molecular interactions between cellulose and high-amylose cornstarch during extrusion processing. Current Research in Food Science. 4(June), 588597.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Dey D, Gu BJ, and Ganjyal GM. 2021. Influence of different sugars on the expansion characteristics of corn starch extrudates. Institute of Food Technologists Annual Meeting. July 2021.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2021 Citation: Dey D, Ek P, Gu BJ, and Ganjyal GM. 2021. Rheological characterization of microcrystalline cellulose-corn starch blends and its impact on the expansion of extrudates. Cereals and Grains Association Annual Meeting 2021.


Progress 02/15/20 to 02/14/21

Outputs
Target Audience:Food processors producing any kind of high fiber foods or intending to produce high fiber foods, including snacks, breakfast cereals, and others. Food ingredient manufacturers, who process high fiber ingredients. Changes/Problems:The difficulty or infeasibility of drawing samples at different stages during extrusion and the impossibility of complete simulation of the conditions inside the extruder brought us to focus on the process induced changes between the raw material and the extrudates rather than on the characteristics of the material during the process. In the currently conducted studies, we will analyze the raw material, the raw blends, as well as the final extrudates. The comparison will help us to understand the molecular interactions that occur in the extruder. The major changes we implemented in our approach was to analyze the molecular changes in the raw material and final product using FTIR. We also understand at this stage, FTIR can currently show qualitative changes in terms of the presence and/or absence of certain functional groups. However, we are still in the process of utilizing the potential of FTIR and supplementary techniques such as XRD and NMR to validate our hypothesis. In addition, we spent a significant amount of time optimizing processes for modifying fiber using the extruder and chemical treatment. Our preliminary results suggested modification of fiber aided in improving the molecular interactions between starch and fiber; therefore, it improved the expansion of extrudates. With the current pandemic situation and the governor's order, we were forced to close down the laboratory completely for about twelve weeks. After we started to return to the lab, only two people were allowed in each of our labs at a given time. This was especially critical for any extrusion work as working on the extruder requires at least four people in relatively close contact. Additional personal protective equipment, namely face shields, helped to slowly ramp up the work. Till now, the lab access is limited, and we are still not running at full capacity. In addition to that, the process of getting access to shared laboratory facilities slowed down significantly. We are still not able to fully access all shared facilities (such as SEM, XRD, and NMR) due to the restrictions given by the different departments as well as the university. Furthermore, Dr. Joyner, one of the Co-PIs, who was responsible for the rheology and tribology equipment, departed from the University of Idaho. Since then, we have been facing access restrictions to the facilities at the University of Idaho to conduct the rheological studies. What opportunities for training and professional development has the project provided?Objective 1 provided great insights into extrusion processing for students. It taught the students a lot about understanding the processed materials and their changes during extrusion processing. This learning outcome is essential for students to effectively choose the material for any extrusion experiment. The studies on raw material characterization further strengthened the students' understanding of the thermal and functional properties of pomaces from different sources. This experimental knowledge was translated into a review article by the three Ph.D. students and published in Frontiers in Sustainable Food Systems. Objective 2 again provided great insights into extrusion processing for students. This objective aimed to understand the influence of independent parameters. The learning outcomes are essential for the students to successfully operate the extruder and to improve the settings. In addition, the analysis of the interaction during extrusion processing requires the students to explore different analysis techniques, including microscopic analysis using Scanning Electron Microscope (SEM), Confocal Laser Scanning Microscope (CLSM), and various spectroscopic techniques, such as Fourier-Transform Infrared (FT-IR) spectroscopy, X-ray Diffraction (XRD), and Nuclear Magnetic Resonance (NMR) spectroscopy. These are trendsetting methods that will help the students to solve many questions regarding the molecular interactions of different food ingredients/components not only during extrusion processing but also during other operations. Being able to understand such interactions is critical for the development of new products. How have the results been disseminated to communities of interest?The results have been disseminated to the scientific community through the poster presentations in the Cereals and Grains 2019 and 2020 conference and the academic showcase of Washington State University. In addition, one scientific paper has been published in the Food hydrocolloid journal, and a review paper has been published in Frontiers in Sustainable Food Systems. What do you plan to do during the next reporting period to accomplish the goals?Objective1: The studies of the effects of cellulose, pectin, sugars, and other potential fibers from fruits (blueberry and cranberry pomace) on starches are being investigated. The remaining data collection will be completed, and the manuscripts will be submitted. In addition, the rheological studies, which have been on hold, has begun and will be completed this next year. Objective 2: As described in the accomplished work for objective 2, several experiments are being studied, and their manuscripts are underway. During the next reporting period, these on-going studies will be completed, and their manuscripts will be published or submitted to different journals. Some concrete and overall conclusions will be obtained. Some starch-fiber combinations will be selected for sensory evaluations. Objective 3: During the next reporting period, all the sensory analysis work will be completed.

Impacts
What was accomplished under these goals? ?Objective 1: Determine the effects of starch and insoluble fiber on the physicochemical and mechanical behaviors of starch polymer matrices. Following the results and main findings in the previous year (Kaisangsri et al. (2019), Wang et al. (2019) and Masli et al. (2018)), the effects of chemically modified apple pomace, cellulose, pectins, and sugars on the physicochemical properties of cornstarch have been conducted. A paper about the effects of high methoxyl and low methoxyl pectins on starch-pectin matrices (Xie et al., 2020) has been published. The manuscripts about the effects of chemically modified apple pomace, cellulose, and sugars are under preparation (80% of data has been collected). Key findings of these studies are as the following: The inclusions of high methoxyl pectin (HMP) and low methoxyl pectin (LMP) showed significantly different impacts on the pasting profile of corn starch. The addition of LMP from 0 to 15 % increased peak viscosity values of cornstarch from 718 to 773 mPa.s, while the addition of HMP decreased the peak viscosity values to 664.3 mPa.s. Furthermore, cornstarch with or without HMP had higher final viscosity than their peak viscosity; on the contrary, cornstarch with LMP had lower final viscosity than their peak viscosity. This result demonstrated that the inclusions of LMP decrease the stability of corn starch pastes, which could be a reason why the LMP-cornstarch mixtures exhibited lower expansion than HMP-cornstarch during extrusion processing. LMP and HMP also affected the thermal properties of cornstarch. Cornstarch with LMP and HMP had slightly higher peak melting temperature and reduced enthalpy values, which can be due to the decreased water availability, leading to partial gelatinization of crystalline regions. The inclusions of cellulose in corn starch also significantly affected the pasting profile and thermal properties of corn starch. As the cellulose content increased, the gelatinization of the mixtures increased from 89.9 oC to 93.2 oC, indicating that cellulose promoted the delay of starch gelatinization. In addition, the peak viscosity and final viscosity values decreased significantly as the cellulose content decreased. For thermal properties, the inclusions of cellulose reduce the enthalpy values of starch-cellulose mixtures. Both pasting profile and thermal properties of cellulose alone were not detected (the curves had a straight line), indicating that cellulose did not transform as the starch does under extrusion conditions. Objective 2: Determine the impact of extrusion-processing parameters on starch-fiber interactions during extrusion and in the final extruded product. Following the results and main findings in the previous year (Kaisangsri et al. (2019), Wang et al. (2019) and Masli et al. (2018)), the effects of chemically modified apple pomace, cellulose, pectins, and sugars on the physicochemical properties of cornstarch have been conducted. A paper about the effects of high methoxyl and low methoxyl pectins on starch-pectin matrices (Xie et al., 2020) has been published. Three posters (Ek et al. (2019) and Dey et al. (2020)) were presented at the Cereals and Grains 19 and 20 conference and Academic Showcase 2020 of Washington State University, respectively. The manuscripts on the effects of chemically modified apple pomace, cellulose, and sugars on the extrusion characteristics of starches are under preparation. Key outcomes of these studies are as the following: The study on the relationship between physicochemical properties and molecular changes in the starch-cellulose mixtures during extrusion processing by Fourier Transform Infrared (FTIR) Spectroscopy was completed. The comparisons of FTIR spectra between raw starch-cellulose mixtures and their extrudates showed notable changes at the 1078-930 cm-1 region, but no new peaks appear. These results explained that no new functional groups were formed between starch and fiber after extrusion, and their molecular interactions cannot be seen. The molecular interactions may occur with the hydrogen bonding and may not be able to be observed by the FTIR, or it may happen inside the extruder and disappear once the extrudate leaves the extruder. The changes at 1078-930 cm-1 explained the rearrangements of the molecules and mainly described their changes in crystallinity. XRD showed that extrusion reduced the overall crystallinity of extrudates compared to the mixtures, and the crystallinity of the starch-cellulose extrudates increased as the cellulose content increased. The manuscript is under review (Ek et al., 2021). Due to the capabilities of our extruder, pure cellulose or fiber cannot be run through the extruder at the conditions used for direct-expanded extrudates. Therefore, a study was designed to increase the cellulose contents to the point at which the mixtures can be run through extruders. 70% of cellulose in the mixture was achieved, and the analysis of the raw mixtures and extrudates are being studied. 90% of the data have been collected, and the manuscript is also under preparation (Ek et al., 2021). To validate the interactions between insoluble fiber and corn starch during extrusion, insoluble fiber from apple pomace was chemically treated. The blends of modified and unmodified apple pomace at varying levels (5,10,15, and 20%) and corn starch were studied. The inter- and intramolecular interactions between cornstarch and modified and unmodified apple pomace before and after extrusion processing were studied using FTIR. The FTIR spectra of raw flour and the extrudates at 5g/100g inclusion of unmodified and modified pomace highlighted changes in the peak at 1035 cm-1. This peak was prominent in the apple pomace extrudates due to the presence of the C-O functional group indicating the interaction between cellulose and lignin. In the case of modified apple pomace extrudates, this peak was absent as lignin was lost during surface treatment, thereby responsible for the higher expansion of these extrudates. These results validate our hypothesis that surface treatment permitted better surface interaction between modified pomace and starch. The results of this study have been analyzed, and the manuscript is currently under preparation (Dey et al., 2021). We further attempted to explore the application of cellulose derivatives such as cellulose nanocrystals (CNC) and microcrystalline cellulose (MCC) in the extrusion of corn starch. These derivatives of cellulose are chemically modified and are reported to have better inter- and intramolecular interactions with starch. Our preliminary results for CNC and MCC inclusion in corn starch showed that CNC had a better expansion ratio as MCC due to the smaller particle size distribution and uniform dispersion into the starch matrix. We are in the process of investigating the thermal, rheological, and spectroscopic analysis of CNC and MCC to validate the findings. The manuscript for this study is under preparation (Dey et al., 2021). Additionally, blends of corn starch, native and waxy, and pomace, blueberry, and cranberry, were extruded in a different study. This design allowed an inclusion level of pomace from 0-100%. The raw material itself, the raw blends, as well as the extrudates, are being studied to determine the inter- and intramolecular interactions as well as the changes induced by extrusion processing. Spectroscopic techniques, including FTIR and NMR, will be applied. The manuscript is in preparation (Richter et al., 2021). Objective 3: Evaluate the sensory attributes of the products produced with different starches and fibers under varying processing conditions. The work for this objective has started this fall semester. An MS student has started working on this objective.

Publications

  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Xie F, Gu BJ, Saunders SR, and Ganjyal GM*. 2020. High methoxyl pectin enhances the expansion characteristics of the cornstarch relative to the low methoxyl pectin. Food Hydrocolloids. 110(2021): 106131.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2019 Citation: Ek P, Gu B, and Ganjyal GM. 2019. Understanding the physical and molecular changes in the mixtures of cellulose and corn starch during extrusion processing using Fourier Transform- Infrared Spectroscopy (FTIR). Cereals and Grains Association annual meeting 2019. 03-05 November 2019, Denver, Colorado, U.S.A.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Dey D, Gu B, and Ganjyal GM. 2020. Exploring the formation of molecular bonds between starch and fiber during production of cereal-based puffed snacks using infrared spectroscopy. Academic Showcase, Washington State University, 2020 April, Washington, U.S.A.
  • Type: Journal Articles Status: Published Year Published: 2021 Citation: Dey D, Richter JK, Ek P, Gu BJ, Ganjyal GM. 2021. A review of food processing by-products utilization in extrusion processing. Frontiers in Sustainable Food Systems, 4, 304.
  • Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Dey D, Gu B, and Ganjyal GM. 2020. Quantification of starch and fiber interactions in direct-expanded snacks manufactured using corn starch and acid-treated apple pomace using FTIR spectroscopy. Cereals and Grains Association Annual Meeting 2020. 10-25 October 2020.


Progress 02/15/19 to 02/14/20

Outputs
Target Audience:The target audience includes i) food research community, ii) food industry including the snacks, breakfast cereals, and other expanded food manufacturers, iii) other industries such as the composites manufacturers who use similar biopolymers for their manufacturing. Changes/Problems:Dr. Helen Joyner (one of the Co-PIs) resigned from UofI. This caused some delay in the rheology work. But. Dr. Joyner has agreed to continue to serve on the graduate student committees and is now helping guide the rheology work. What opportunities for training and professional development has the project provided?Three Ph.D. students and 1 undergraduate student is being trained on this project. Ms. Pichmony Ek - Ph.D. Candidate - (started in Aug 2017) working on fundamental aspects of physical and molecular changes of starch and fiber biopolymers during extrusion processing. Ms. Debomitra Dey - Ph.D. Student - (started in Jan 2019) working on understanding how the fiber with modified surfaces react with starch during extrusion processing to affect the expansion process. Ms. Jana Ritcher - Ph.D. Student - (started in Jan 2020) working on the investigation of molecular changes of starch-fiber mixtures and their monomer model mixtures using XRD and NMR. Undergraduate student - Marina Ikuse (started in Jan 2020) assisting with the various laboratory experiment One Ph.D. student presented their research work as a poster at the Cereals and Grains Association inDenver, Colorado, U.S.A. during November 2019. All students are being provided with great opportunities to learn new research techniques and work with world-class researchers. How have the results been disseminated to communities of interest?The following two journal articles have been published: 1. Kaisangsri N, Kowalski RJ, Kerdchoechuen O, Laohakunjit N, Ganjyal GM. 2019. Cellulose fiber enhances the physical characteristics of extruded biodegradable cassava starch foams. Industrial Crops and Products. 142: 111810. https://doi.org/10.1016/j.indcrop.2019.111810 2. Wang S, Kowalski RJ, Kang Y, Kiszonas AM, Zhu M, Ganjyal GM. 2019. Impacts of the inclusion of various fruit pomace types on the expansion of corn starch extrudate. LWT. 110:223-230. https://doi.org/10.1016/j.lwt.2019.03.094 The following poster was presented at the Cereals and Grains Association: 1. Ek P, Gu B, and Ganjyal GM. 2019. Understanding the physical and molecular changes in the mixtures of cellulose and corn starch during extrusion processing using Fourier Transform- Infrared Spectroscopy (FTIR). Cereals and Grains Association annual meeting 2019. 03-05 November 2019, Denver, Colorado, U.S.A. ?Additionally, another 6 manuscripts are in preparation from the work that has been completed: EK P, Gu B, andGanjyal GM. 2020. Extrusion characteristics of select whole lentil varieties. Journal of Food Science.In Preparation. EK P, Gu B, andGanjyal GM. 2020. Relationship of physicochemical properties and molecular changes in the mixtures of cellulose and corn starch during extrusion processing. LWT - Food Science and Technology.In Preparation. EK P, Gu B, Saunders SR, andGanjyal GM. 2020. Effects of cellulose on the physicochemical and molecular changes of native corn starch during extrusion processing. Carbohydrate Polymers.In Preparation. Dey Dand Ganjyal GM. 2020. Direct Expansion of Starch during Extrusion Processing and the Factors Influencing Expansion: A Review. Comprehensive Reviews in Food Science. Dey Dand Ganjyal GM. 2020.High Fiber Inclusion in Direct Expansion in Extruded Products: A Review. Comprehensive Reviews in Food Science. Dey Dand Ganjyal GM. 2020.Surface interactions between starch and fiber during extrusion processing of corn starch incorporated with modified and unmodified apple pomace. Journal of Food Science. What do you plan to do during the next reporting period to accomplish the goals?We will continue with the following - 1. Further, explore the starch and fiber interactions in their mixture forms before and after extrusion using NMR and XRD techniques. 2. Continue the work studying the impacts of the surface modifications of the fibers on the physicochemical interactions with starches. 3. Evaluate the sensory attributes of the products made with the different fibers and starches.

Impacts
What was accomplished under these goals? About 40% of the proposed work has been completed. We have worked on understanding the changes in the mixtures of the starch and different types of fibers using MVAG and Rheometer. A significant number of extrusion trials have been conducted to understand the impacts of different fibers (cellulose, various types of pomace, modified apple pomace, and microcrystalline cellulose) and fiber with different particle sizes. We were able to make significant progress in exploring the potential of FTIR as a tool to identify the potential chemical interactions between the starch and fibers in the extruded products. The FTIR work has taken us into the direction of focus on crystallinity changes in the products. Now we are heavily focusing on the use of NMR and XRD to explore the potential chemical interactions that could be happening during the extrusion process. Objective 1: Determine the effects of starch and insoluble fiber on the physicochemical and mechanical behaviors of starch polymer matrices. Characterization of the chemical composition and physical properties of insoluble fibers from different sources and their effect on the starch polymer have been done. The results and main findings have been published as three papers in peer-reviewed journals (Kaisangsri et al. (2019), Wang et al. (2019), and Masli et al. (2018)). Masli et al., 2018 found that Fiber-rich food processing byproduct affected differently on the pasting properties (gelatinization temperature and peak viscosity) of starch-fiber mixtures. As a result, the expansion characteristics of cornstarch-based extrudates were impacted significantly due to their variations in chemical composition profile and their microstructural characteristics. Wang et al. (2019) observed that pectin content and sugar content of the insoluble fibers from various fruit pomace might have helped in improving the expansion ratio of the extrudates, while their crystallinity significantly decreased the expansion. The correlation study explained there may be the interactions or the synergy between compositions in insoluble fibers, which improve or reduce the physicochemical properties of starch polymer matrices. To further identify which components of the insoluble fibers positively or negatively affected the starchy extrudates, the combination of different starches and each component of insoluble fibers (cellulose, hemicellulose, pectin, sugar) need to be further studied. The combination of cellulose fiber and cassava starch was used in the study by Kaisangsri et al., 2019. The main finding was that 5% of cellulose fiber helped in improving the expansion and structure of cassava foam, while 10% of cellulose fiber reduced the expansion and more ruptures in the microstructure of extrudates. The effect of cellulose content on the pasting properties of corn starches with different amylose content was studied. At the same cellulose content, cellulose affected the viscosity profiles of corn starches at different degrees. This results primarily explained the interaction of starch and cellulose. Thermal properties and rheological properties of the cornstarch mixtures are being studied. Objective 2: Determine the impact of extrusion-processing parameters on starch-fiber interactions during extrusion and in the final extruded product. To determine the impact of extrusion-processing parameters on starch-fiber interactions, the study on the relationship of physicochemical properties and molecular changes in the mixtures of cellulose and corn starch during extrusion processing is being studied, and the manuscript is under preparation (Ek et al., 2020). Due to the capabilities of our extruder, pure cellulose or fiber cannot be run through the extruder at the conditions used for direct-expanded extrudates. Therefore, a study was designed to increase the cellulose contents to the point at which the mixtures can be run through extruders. 70% of cellulose in the mixture was achieved, and the analysis of the raw mixtures and extrudates are being studied. The manuscript is also under preparation (Ek et al., 2020). The study of the effect of modified and unmodified apple pomace on surface interactions between corn starch and fiber during extrusion processing is being studied (Dey et al., 2020). Objective 3: Evaluate the sensory attributes of the products produced with different starches and fibers under varying processing conditions. The work for this objective will start during the year 2021. This is because we will be using the selected samples from the objective #2 for the thorough sensory testing.

Publications

  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Wang S , Kowalski RJ , Kang Y, Kiszonas AM, Zhu M, Ganjyal GM*. 2019. Impacts of the inclusion of various fruit pomace types on the expansion of corn starch extrudate. LWT. 110:223-230. https://doi.org/10.1016/j.indcrop.2019.111810
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: Kaisangsri N , Kowalski RJ , Kerdchoechuen O, Laohakunjit N, Ganjyal GM*. 2019. Cellulose fiber enhances the physical characteristics of extruded biodegradable cassava starch foams. Industrial Crops and Products. 142: 111810. https://doi.org/10.1016/j.lwt.2019.03.094


Progress 02/15/18 to 02/14/19

Outputs
Target Audience:During the first year of the project, we have made significant progress in the project work. The target audience for the project incldues the food processing industry, including the manufacturers of fiber ingredients, snacks and breaskfast cereal products, and any other companies using extrusion processing technology to make the food products. Changes/Problems:We have not had any major issues so far in the project. We had some intial delay in hiring the Ph.D. students into the project, due to the semster schedules. But, we do have two students on the project now and we hope that the work will continue without any major issues. We have not had any major issues in the approach of the project. What opportunities for training and professional development has the project provided?Two students have been hired on to this project and are being trained in the technical aspects of the project as well as the teamwork aspects. This project is providing excellent opprotunities for these two Ph.D. students. In the summer of 2019, we will be hiring one or two undergraduate students to work on the project. How have the results been disseminated to communities of interest?Yes, some of the results have already been disseminated to the communities of interest. This has been done via the one publication thus far. We will continue to disseminate the information generated through the project to the community through different avenues. In the year 2019, 2020, and 2021, we will present the data at the IFT annual meetings and any other potential locations, as they come along. We have also had meetings with our industry advisory committee about the project progress and dissemintate the information through the committee. What do you plan to do during the next reporting period to accomplish the goals?For the next year, we will continue to work on Objectives #1 and #2. This work will go into the following year as well. We will strive to publish more papers and present the data at scientific meetings, as we gather data through the work. We beleive we are progressing at a very good pace and should be on track to finish the project in time.

Impacts
What was accomplished under these goals? Objective 1: Determine the effects of starch and insoluble fiber on the physicochemical and mechanical behaviors of starch polymer matrices. Hypothesis:Certain properties of starch (thermal and rheological) and insoluble fiber (surface characteristics, flexibility and particle size distributions) will significantly correlate to the final physicochemical and mechanical properties of the ingredient matrix and final product after processing. Accomplishments: We are conduting experiments related to this objective. Two students (Pichmony Ek and Debomitra Dey) have started working on thsi objective. We ahve selected the different fibers and the starches and are currently conducting experiments, to understand the behaviour of the mixtures of the starches and the fibers, under different shear and temperatrue condutions uusing a rheometer. A separate stream of work is also udnerway, to characterize the fibers, both chemically and physically. Objective 2: Determine the impact of extrusion-processing parameters on starch-fiber interactions during extrusion and in the final extruded product. Hypothesis: Changing the amounts of mechanical and thermal energy imparted to the extruded materials will significantly impact the expanded cellular structure by causing changes in starch properties, fiber distribution, and binding in the starch matrix. Accomplishments: We have conducted preliminary extrusion work, on the combintation of different fiber sources and corn starch, to understand the effects of the fiber sources on the final product quality. One paper has been published and another one is in review. Objective 3: Evaluate the sensory attributes of the products produced with different starches and fibers under varying processing conditions. Hypothesis: Reducing the disruption of the starch matrix will yield products with sensory texture attributes that more similarly align with those produced from refined grain. Sensory attributes will be related to the physical- and mechanical measurements gained in Objectives 1 and 2. Accomplishments: We have not started to work on this objective, as this will be addressed in the final year of the project, upon the completion of the Objectives #1 and #2.

Publications

  • Type: Journal Articles Status: Published Year Published: 2018 Citation: Masli MDP, Gu BJ, Rasco BA, and Ganjyal GM. 2018. Expansion characteristics of cornstarch extrudates incorporating fiber-rich food processing byproducts. Journal of Food Science. 83(9): 2117-2327.
  • Type: Journal Articles Status: Under Review Year Published: 2019 Citation: Wang S, Graham T, Saunders SR, and Ganjyal GM. 2019. Effects of Fruit Pomace Chemical and Physical Properties on the Expansion Characteristics of Corn Starch Extrudates. LWT - Food Science and Technology.