DEVELOPMENT OF HEALTHY AND NUTRITIOUS FINGER FOOD FROM SPROUTED QUINOA AND MILLETS USING EXTRUSION TECHNOLOGY

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: REVISED
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1012931
• Project No.: SD00H640-18
• Project Start Date: Oct 1, 2017
• Project End Date: Sep 30, 2022

Project Director
Muthukumarappan, K.

Recipient Organization
SOUTH DAKOTA STATE UNIVERSITY
PO BOX 2275A
BROOKINGS,SD 57007

Performing Department
Agricultural & Biosystems Engineering

Non Technical Summary
Quinoa is a naturally gluten-free grain. It is high in protein and one of the few plant foods that contains all nine essential amino acids. In addition, large amounts of flavonoids, quercetin and kaempferol are also found. Germination of quinoa breaks down the phytic acid and increases Gamma-amino butyric acid content and mineral absorption. Hence, a snack derived from quinoa would increase options for healthy feeding. Likewise, millets are a diverse group of small seeded crops belonging to the Poacea family and are commonly termed 'ancient grains'. Proso millet (true millet, common millet, hog millet, yellow hog, etc.) is the only millet grown as a grain crop in USA, with main production in the states of Nebraska, Colorado and South Dakota, where it is often employed as rotational crop with winter wheat. A short growing period, lower water requirement and improvement in wheat, corn and sorghum yield when rotated with these crops make growth of millet desirable from an agricultural standpoint. Millets are also a good source of phenols and flavonoids, contributing to their antioxidant activity. Millet grain contains more protein, fat and carbohydrate than maize, rice and sorghum. Combined with its low cost, this makes it a highly affordable source of high-value nutrition especially for those doing hard labor. The grain is also rich in important minerals like calcium, phosphorus and iron and in methionine, an essential amino acid. It also possesses a high biological value, which is needed for the maintenance of nitrogen equilibrium of the body. The high fiber content of millet helps in many ways as it prevents constipation, high cholesterol formation and intestinal cancer. Germination reduces anti-nutrients thereby improving nutritional and functional properties of millet and the mousy odor of damp millet is eliminated. The protein quality is also improved by germination by increasing GABA amino acid. Extrusion is a versatile, cost-effective process that can be used to create ready-to-eat cereals and snacks from grains. The extrusion process is a multivariable technique that involves the interaction among flour characteristics, such as moisture content and chemical composition, as well as processing parameters, including temperature, screw speed, feed rate and screw configuration. Flour moisture influences the degree of cook and shear experienced by flour components.The objective is to develop a healthy snack from sprouted quinoa and millet that can be used as a by optimizing the extrusion process. Millets and white quinoa seeds will be soaked in cold water and then allowed to germinate for various time periods. The flours will be processed in single and twin-screw extruders. Effects of germination time (0-48 hrs), feed moisture content (15-20 %), screw speed (100-200 rpm) and temperature (90-140°C) on the physical characteristics of the extrudates will be investigated using response surface methodology (RSM). The physical properties color, bulk density, unit density, water absorption index (WAI), water solubility index (WSI), texture and expansion ratio will be measured.

Animal Health Component

0%

Research Effort Categories

Basic

50%

Applied

50%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
501	1599	2020	100%

Knowledge Area
501 - New and Improved Food Processing Technologies;

Subject Of Investigation
1599 - Grain crops, general/other;

Field Of Science
2020 - Engineering;

Keywords

snack

products

extrusion

technology

Goals / Objectives
Goals / ObjectivesThe overall goal of the project is to develop healthy snack products from sprouted quinoa and millets using extrusion technology. Specific objectives of this project are:Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and milletsObjective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets

Project Methods
Objective 1: Develop an optimal germination process to enhance nutritional and physical characteristics of quinoa and milletsGermination or malting of cereal grains may result in some biochemical modifications and produce malt with improved nutritional quality that can be used in various traditional recipes. Germination of quinoa and millet grains increases the free amino acids and total sugars and decreases the dry weight and starch content. Increases in lysine, tryptophan, and non-protein nitrogen also occur. Germination also appreciably improved the in vitro protein (14% to 26%) and starch (86% to 112%) digestibility in finger millet. However, literature review shows that there has not been protein quantification of proso millet and white quinoa. The improvement in protein digestibility after germination, soaking, debranning, and dry heating can be attributed to the reduction of anti-nutrients such as phytic acid, tannins, and polyphenols, which are known to interact with proteins to form complexes. In addition, the changes in nutrient content of grains after germination can be attributed to the utilization by growing sprouts. It has also been found that the in vitro extractability and bioaccessibility of minerals such as calcium, iron, and zinc were increased in millet by germination; however, the anti-nutritional factors such as phytic acid were decreased and there is a scope for research in quinoa. Furthermore, the relative in vitro solubility of iron was doubled by the germination. Therefore, malting generally improves the nutrient content and digestibility of foods and it could be an appropriate food-based strategy to derive iron and other minerals maximally from food grains.Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and milletsThe main aim of this objective is to optimizeextrusion processing parameters to develop the processed healthy snack product. During extrusion processing, food materials undergo many order-disorder transitions such as starch gelatinization, protein denaturation, components interactions, and browning reactions and thus modify the ingredients' molecular structure, change their functionalities and subsequently alter the extrudates physical and biological qualities. These changes can result in improved organoleptic properties, increased nutrient availability, improved antioxidant properties, and inactivation of heat labile toxic compounds and enzyme inhibitors.Ready to eat extrudates will be developed using a single and twin-screw extruder. The single screw extruder (Brabender Plasti-corder Extruder Model PL2000, Hackensack, NJ) has a barrel length to screw diameter ratio (l/d) of 20:1. The extruder is fitted to a 7.5 hp motor, which has a provision to adjust the screw speed and barrel temperatures. Extrusion will be carried out using a screw compression ratio of 3:1. Once the extruder conditions are stabilized, ~6 kg samples will be extruded for each flour by optimizing the extrusion parameters, such as; screw speed (90-140 rpm), temperature (90-140°C), and flour moisture content dry basis (15-25%), separately to identify optimal conditions critical to obtaining nutritionally and functionally enhanced product. Extrusion will facilitate protein denaturation, starch gelatinization thereby enabling the protein digestibility.Characterizing the extrudates by determining the physical properties such as true and bulk density, porosity, water solubility index, and water adsorption index, hardness, compressibility, water activity and thermal properties will allow both targeted applications and information to guide extrusion process optimization/modifications in maximizing yields for specific applications. Therefore, we will evaluate above-mentioned properties using standard protocols.GABA amino acid for sprouted and unsprouted grains will be determined by HPLC method. Antioxidant activity will be evaluated by free radical scavenging activity as follows: Five grams of processed product will be extracted first by homogenization in a high-speed homogenizer with 70% ethanol for 5 minutes. Filtrate will be evaporated under nitrogen and finally the extracted will be freeze-dried. Freeze dried extract will be used to evaluate the antioxidant activity. Free radical scavenging activity will be measured using Mellors and Tappel method. DPPH (2,2-dihpenyl-1-picrylhydrazyl), a stable free radical will be dissolved in ethanol to give a 100-uM solution. To 3.0 ml of ethanolic solution of DPPH, add 0.5 ml of the test solution in ethanol. The decrease in DPPH absorption at 517 nm will be measured after 10 minutes. The actual decrease in absorption induced by the test compound will be calculated by subtracting that of the control. The assay will be conducted in triplicate for each sample. Total anti-oxidative activity will be compared against synthetic antioxidant such as BHA, BHT and TBHQ.Statistical analysis: A fractional factorial design of different combinations for each experiment will be conducted. The data will be analyzed with GLM procedure to determine the main, interaction and treatment combination effect in Design Expert Software using a type I error (a) of 0.05.

Progress 10/01/19 to 09/30/20

Outputs
Target Audience:Research community: Specifically we are targeting scientists working in extrusion processing research. An understanding of our research results will help them develop hypotheses that will advance their own research programs. We targeted these individuals through peer reviewed publications and presentations at scientific meetings. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Gabriela Swamy, Ph.D. student, entire reporting period, has tested these novel technologies and been trained in food engineering principles and novel food processing technologies. The graduate student was able to increase her professional development activities by attending food processing related virtual conferences. How have the results been disseminated to communities of interest?Presentations were provided at the virtual food technology meetings. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and millets This objective was completed in the previous years and no additional work is planned. Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets Task 2: Single screw extrusion of sprouted quinoa This task was completed previous year and findings are reported. Task 2b: Single screw extrusion of sprouted quinoa + corn flour Using the optimized conditions for quinoa germination, the quinoa-corn flour blend was extruded under various extrusion conditions in a single screw extruder. The physical properties of the extrudates will be measured and the findings will be reported. Task 3: Twin screw extrusion of sprouted quinoa Using the optimized conditions for germination, quinoa flour will be extruded under various extrusion conditions in a twin screw extruder. The physical properties of the extrudates will be measured and the findings will be reported.

Impacts
What was accomplished under these goals? Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and millets (100% Accomplished) This objective was completed and reported on in the prior annual reports. Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets (60% Accomplished) Task 1: Single screw extrusion of millets This task was completed and reported in the previous annual report. Task 2: Single screw extrusion of sprouted quinoa flour Soaking and germination pretreatments of quinoa were carried out to reduce the saponin and phytic acid content, and therefore increase protein and starch digestibility. Single-screw extrusion processing of sprouted quinoa flour was studied using a response surface design to understand the influence of feed moisture content (15-25% w.b.), die temperature (80-140°C), screw speed (90-220 rpm), and germination time (0-4 days) on the physical and physico-chemical properties of sprouted quinoa extrudates. Extrusion experiments were carried out using a single screw extruder (Brabender Plasti-corder, model PL 2000, South Hackensack, NJ). The physical properties of the extrudates were assessed using standard procedures described in the previous reports. The following responses of the extrudates were measured and the values ranged from: bulk density (116-154 kg/m3), hardness (1.05-1.8 N), water solubility index (11.5-16.5%), water absorption index (2.36-3.51), total color difference delta E (14.8-21.7), expansion ratio (2.52-3.75), protein digestibility (80.5-86.5%), and starch digestibility (80.1-85.8%). Both feed moisture content and extruder die temperature had statistically significant effects on all the extrudate characteristics. Extruder screw speed had minimal effect on the extrudate properties. As the germination time increased, the starch and protein digestibility of the extrudates increased. In addition to soaking and germination, extrusion was most effective in improving protein and starch digestibility. By applying the methodology of the desired function, the optimized process variables were moisture 15%, temperature 115°C, screw speed 185 rpm, and Day 4 germinated flour with bulk density = 118.8 kg/m3, hardness = 1.13 N, water solubility index = 16.5, water absorption index = 3.4, total color difference delta E = 20.6, expansion ratio = 3.75, protein digestibility = 86.3%, and starch digestibility = 85.7%, with overall desirability value of 0.999. Overall, the quinoa processed via the range extrusion conditions showed moderate expansion characteristics as compared to widely used cereal grains, suggesting that quinoa is not well suited for making direct expanded products as compared to corn. However, this may be more useful in the products where direct expansion is not an important textural quality. Task 2b: Single screw extrusion of sprouted quinoa + corn flour Using the optimized conditions for quinoa germination, the quinoa-corn flour blend was extruded under various extrusion conditions in a single screw extruder. The physical properties of the extrudates will be measured and the findings and resulting impacts will be reported in the next year progress report.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Muthukumarappan, K., A. Sobhan, and L. Wei. 2020. Biosensors and biopolymer-based nano composites for smart food packaging: Challenges and opportunities. Invited Panel Paper, KOSFOP 2020, 41st International Symposium on New Challenges in Smart Food-Tech. Aug 19-21. Yeosu-City, South Korea. (Virtual)
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Muthukumarappan, K. 2020. Current innovations in agricultural and biosystems engineering. Invited keynote address, 2020 Agricultural Graduate Students Conference. May 28-29. TNAU. Coimbatore, India. (Virtual)
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Muthukumarappan, K. 2020. Extrusion processing: Challenges and opportunities. Invited keynote address, 2020 IIFPTs Meet the Editor Webinar Series. May 22. Indian Institute of Food Processing Technology. Thanjavur, India. (Virtual)
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Muthukumarappan, K. 2020. Biofuel from food wastes. Invited keynote address, 2020 Webinar Series on Novel Approaches in Food Processing. April 10. Amity University, Noida, India. (Virtual)

Progress 10/01/18 to 09/30/19

Outputs
Target Audience:Research community-- Specifically we are targeting scientists working in extrusion processing research. An understanding of our research results will help them develop hypotheses that will advance their own research programs. We targeted these individuals through peer reviewed publications and presentations at scientific meetings. Changes/Problems:Millets and quinoa have more protein when compared to the other cereal grains. These grains can be also used to make puffed snacks by a minor addition of corn flour. The single screw extraction of the flour blend is also being investigated. What opportunities for training and professional development has the project provided?Gabriela Swamy, Ph.D. student, entire reporting period, has tested these novel technologies and been trained in food engineering principles and novel food processing technologies. The graduate student was able to increase her professional development activities by attending and presenting two papers at the IFT Annual Meeting, New Orleans. How have the results been disseminated to communities of interest?Presentations were provided at the IFT 19 meeting in New Orleans. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and millets This objective is completed and no additional work is planned. Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets Task 2: Single screw extrusion of sprouted quinoa The physical properties of the extrudates will be measured. Task 2b: Single screw extrusion of sprouted quinoa + corn flour Using the optimized conditions for quinoa germination, the quinoa-corn flour blend will be extruded under various extrusion conditions in a single screw extruder. The physical properties of the extrudates will be measured Task 3: Twin screw extrusion of quinoa Using the optimized conditions for germination, quinoa flour will be extruded under various extrusion conditions in a twin screw extruder. The physical properties of the extrudates will be measured.

Impacts
What was accomplished under these goals? Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and millets (100% Accomplished) This objective was completed and reported on in the prior annual report. Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets (40% Accomplished) Task 1: Single screw extrusion of millets Based on the results of our prior experiment, the lower expansion ratio values observed for millet may be attributed to the fact that the millet flour has higher amounts of protein, fiber, and fat as compared to cereal grains. Hence an experiment was designed to improve extrudate properties by value addition of corn. This is described under Task 1b. Task 1b: Inclusion of corn flour to improve extrudate properties Extrusion experiments were carried out using a single screw extruder (Brabender Plasti-corder, model PL 2000, South Hackensack, NJ). The extruder had a screw diameter of 19 mm, a length to diameter ratio of 20:1, nominal compression ratio of 3:1, and a die opening of 3 mm. The inner barrel had a grooved surface to ensure zero slip at the wall. The barrel was divided into independent electrically heated zones (feed zone, central zone, and die) cooled by air. Feed zone temperature was kept constant at 70°C throughout the experiments. The extrusion parameters comprising the independent variables were temperatures at the central and die end zone of the barrel (90, 115, and 140°C), screw speed (100, 150, and 200 rpm), feed moisture content (15, 17.5, and 20% wb) and millet:corn blend ratio (90:10, 80:20, and 70:30). Expansion ratios of sprouted millet extrudates ranged from 3.47 to 4.32. The density of dry extrudates varied between 88 and 273 kg/m3. Feed moisture has been recognized as a primary factor affecting extrudate expansion and density. Water Absorption Index (WAI) and Water Solubility Index (WSI) values for all the extrudates ranged from 2.2 to 3.1 g/g and from 13.6 to 16.8%, respectively. WAI increased with increasing temperature and screw speed, indicating complete gelatinization. Differences in L value for color ranged from 78.3 to 86.4, while total color change (ΔE) in the extrudates ranged from 2.9 to 4.4. Hardness of extrudates was significantly (P < 0.01) affected by linear effects of all 3 independent variables. Task 2: Single screw extrusion of quinoa Extrusion experiments were carried out using a single screw extruder (Brabender Plasti-corder, model PL 2000, South Hackensack, NJ). The extrusion parameters comprising the independent variables were temperatures at the central and die end zone of the barrel (90, 115, and 140°C), screw speed (100, 150, and 200 rpm) and feed moisture content (15, 17.5, and 20% wb). The physical properties of the extrudates will be assessed and included in the next reporting period.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Swamy, G.J., K. Muthukumarappan. 2019. Development of healthy and nutritious finger food from sprouted quinoa using extrusion technology. IFT 19, New Orleans, LA. June 4.
• Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: Swamy, G.J., K. Muthukumarappan. 2019. Optimization of extrusion process parameters to develop a ready-to-eat finger food from sprouted millets. IFT 19, New Orleans, LA. June 4

Progress 10/01/17 to 09/30/18

Outputs
Target Audience:Personnel involved in food processing industry-- Specifically we are targeting professionals who work for the food processing industry. These professionals are most likely to benefit from knowledge generated by this project. These personnel were targeted through email communications and conference presentations. Research community-- Specifically we are targeting scientists working in extrusion processing research. An understanding of our research results will help them develop hypotheses that will advance their own research programs. We targeted these individuals through peer reviewed publications and presentations at scientific meetings.? Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Gabriela Swamy, Ph.D. student, entire reporting period, has tested these novel technologies and been trained in terms of food engineering principles and novel food processing technologies. The graduate student was able to increase her professional development activities by attending and presenting two papers at the IFT Annual Meeting, Las Vegas, NV. How have the results been disseminated to communities of interest?Presentations were provided at the IFT 17 meeting in Las Vegas. What do you plan to do during the next reporting period to accomplish the goals?Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and millets This objective is completed and no additional work is planned Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets Task 2: Single screw extrusion of quinoa Using the optimized conditions for germination, quinoa flour will be extruded under various extrusion conditions in a single screw extruder. The physical properties of the extrudates will be measured Task 3: Twin screw extrusion of quinoa Using the optimized conditions for germination, quinoa flour will be extruded under various extrusion conditions in a twin screw extruder. The physical properties of the extrudates will be measured

Impacts
What was accomplished under these goals? Objective 1: Develop an optimal germination process for enhancing the nutritional and physical characteristics of quinoa and millets (100% Accomplished) Quinoa seeds naturally have saponin on them, a bitter substance that deters birds and other wildlife from eating them. Saponins are anti-nutrients that affect the gastrointestinal lining, contributing to leaky gut syndrome and autoimmune disorders. Soaking removes the saponins effectively. Similarly, millet is so important because of its uniquely high content of nutrients, including impressive starch levels, calcium, iron, potassium, zinc and magnesium. Millet can help in proper gastrointestinal functioning and eliminate problems like constipation, excess gas, bloating, and cramping. Sprouting and soaking also decreases the level of phytic acid, an enzyme inhibitor, that can block absorption of vitamins and minerals, and can cause poor digestion and disruption of healthy gut bacteria. Germination increases the free amino acids and total sugars and decreases the dry weight and starch content. Increases in lysine, tryptophan, and non-protein nitrogen also occur. Trials were conducted to determine the optimum soaking time (6, 8, 10, 12, 24 h) and germination time (24, 48, 72h) for quinoa and millet. After soaking for 8 h, the bright-white colored hypocotyls emerged from the quinoa seeds. The germination efficiency was more than 90%. The sprouts had a slightly crisp texture and mild flavor, and their appearance was similar to those of proso millet sprouts. The protein content dropped significantly on the 4th day of germination and a simultaneous increase in the hypocotyl length was observed. The optimized soaking time is 8 h and germination time is 72 h. After soaking for 12 h, the bright-white colored hypocotyls emerged from the millet seeds. The optimized soaking time is 12 h and germination time is 72 h. Objective 2: Develop an optimal extrusion process for retaining/enhancing the nutritional and physical characteristics of quinoa and millets (20% Accomplished) Task 1: Single screw extrusion of millets Extrusion experiments were carried out using a single screw extruder (Brabender Plasti-corder, model PL 2000, South Hackensack, NJ). The extruder had a screw diameter of 19 mm; a length to diameter ratio of 20:1; nominal compression ratio of 3:1; and a die opening of 3 mm. The inner barrel had a grooved surface to ensure zero slip at the wall. The barrel was divided into independent electrically heated zones (feed zone and central zone and die) cooled by air. Feed zone temperature was kept constant as 70°C throughout the experiments. The extrusion parameters comprising the independent variables were temperatures at the central and die end zone of the barrel (90, 115 and 140°C), screw speed (100, 150 and 200 rpm), and feed moisture content (15, 17.5 and 20% wb). Expansion ratios of sprouted millet extrudates ranged from 2.47 to 4.12 (Control: 1.23 - 1.59). The lower ER values observed for millet may be attributed to the fact that the millet flour had higher amounts of protein, fiber, and fat as compared to cereal grains. The density of dry extrudates varied between 108 and 473 kg/m3. Feed moisture has been recognized as a primary factor affecting extrudate expansion and density. WAI and WSI values for all the extrudates ranged from 2.2 to 3.1 (g/g) and from 13.6 to 16.8 (%) respectively. WAI increased with increasing temperature and screw speed indicating complete gelatinization. Differences in L value for color ranged from 68.3 to 71.4 and total color change (ΔE) in the extrudates ranged from 7.9 to 18.4. ΔE represents the total color difference compared to the color of unsprouted millet flour. Hardness of extrudates was significantly (P < 0.01) affected by linear effects of all 3 independent variables.

Publications

• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: G.J. Swamy, K. Muthukumarappan. 2017. Development of healthy and nutritious finger food from sprouted quinoa using extrusion technology. IFT 17, Las Vegas, NV. June, 28
• Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: G.J. Swamy, K. Muthukumarappan. 2017. Optimization of extrusion process parameters to develop a ready-to-eat finger food from sprouted millets. IFT 17, Las Vegas, NV. June, 28