Source: UTAH STATE UNIVERSITY submitted to NRP
UNDERSTANDING ROLE OF MATERIAL PROPERTIES FOR OPTIMIZING FUNCTIONALITY OF CHEESE MATRICES
Sponsoring Institution
State Agricultural Experiment Station
Project Status
COMPLETE
Funding Source
STATE
Reporting Frequency
Annual
Accession No.
1023579
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Jun 29, 2020
Project End Date
Jun 30, 2024
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UTAH STATE UNIVERSITY
(N/A)
LOGAN,UT 84322
Performing Department
Nutrition, Dietetics and Food Sciences
Non Technical Summary
Cheese is a popular food commodity consumed globally and provides a good return on investment for manufacturers. Consumers have a variety of choices both in the form in which it is purchased (such as blocks, shreds, slices, and spreads) and type of cheese (including processed cheeses designed for use as snacks, in recipes, and for its melting properties). Offering a consistent quality cheese at an affordable price, while meeting consumer expectations, is a challenging task. Being able to predict functional behavior of the cheese will allow cheese manufacturers to better meet consumer expectations and develop products to meet changing consumer lifestyle needs. Each cheese type has unique sensory and textural attributes which can be related to the material characteristics of the cheese. Such characteristics depend upon factors such as composition, processing parameters and storage conditions. To have consistent quality in the finished cheese it is necessary to control the entire cheese manufacturing process from farm to fork and to understand the inter-relationship between material properties and cheese performance. Measurement of material properties such as wear behaviour, texture and rheology will be related to functional behavior of cheeses such as shredding, melting, blistering, oiling off and flow behavior. This project will establish linkages between cheese manufacturing conditions, material characteristics and functional performance. Material properties will be studied in relation to three aspects of functional behavior: (1) conversion of cheese from blocks into shred (machinability and shreddability) , (2) flow characteristics when cheese is melted (meltability) and (3) flow characteristics when pressure is applied to cold cheese (squeezability). A predictive model will be developed by correlating wear behavior with various textural attributes and shredding performance of processed cheese. Hot melt and flow properties will be studied using Mozzarella cheese of varying composition based upon performance on a pizza. Squeezing flow attributes of cream cheese will be studied by varying composition using various dairy protein and phospholipid-based ingredients and under various processing conditions. This study will improve the scientific basis for understanding how material properties of cheese can be used in predicting quality characteristics of various cheese matrices and hence provide tools for cheese manufacturers to have better control on cheese quality.
Animal Health Component
30%
Research Effort Categories
Basic
60%
Applied
30%
Developmental
10%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
5023430200080%
5013430202020%
Knowledge Area
501 - New and Improved Food Processing Technologies; 502 - New and Improved Food Products;

Subject Of Investigation
3430 - Cheese;

Field Of Science
2020 - Engineering; 2000 - Chemistry;
Goals / Objectives
Overall goal of this project is to investigate whether determination of material properties in various cheese matrices could be established as a quality control tool for predicting final performance of cheese. Specific objectives are: (1) Determine whether wear behavior can predict shreddability of processed cheeses containing varying amount of intact casein and emulsifying salt (Milestone/Target Date: April 30, 2021); (2) Understand how composition and extent of proteolysis would influence melt, hot flow, stretchability and overall baking performance of Mozzarella cheese (Milestone/Target Date: July 31, 2022); (3) Determine how formulation and processing conditions while making cream cheese influence cold flow (squeeze flow) properties and whether it is possible to design a clean label squeeze flow product (Milestone/Target Date: December 31, 2024).
Project Methods
This project is divided into three major components: (1) correlating wear behavior with shredding ability of process cheese; (2) Studying factors (proteolysis, utilization of galactose and Calcium content) affecting baking performance of Mozzarella cheese; (3) Developing a clean label squeezable cream cheese product.All three type of cheeses. i.e. process cheese, Mozzarella cheese and cream cheese will be manufactured in Gary H. Richardson Dairy Products Laboratory (DPL) using standard protocols at Utah State University from the milk obtained from Utah Agriculture Experiment station. Cheese samples will be subjected for rheological, textural, microstructural, wear behavior, biochemical tests. Cheese proximate composition (final pH, moisture, intact casein, fat, and ash) will be determined using standard methods for dairy products. Intact casein content will be determined using gel electrophoresis methods. Cheese microstructures will be characterized using confocal scanning laser microscopy using protein (Fast Green) and fat (Nile red) specific fluorescent dyes. Cheese viscoelastic properties will be characterized using strain and frequency sweeps on MCR 302 rheometer. Strain sweeps will be conducted at 5°C using 1 Hz frequency to determine linear viscoelastic (LVE) limit of the samples. Frequency sweeps will be conducted within LVE limit by applying frequency in the rage of 0.1 -100 Hz using 0.5% strain amplitude at 5°C. This test will indicate how sensitive is material towards rate of shear deformation that is applied during slicing or shredding. Cheese melt behavior will be characterized using temperature sweeps (5-75°C). Texture profile analysis on cheese samples will be conducted on Texture Analyzer (Texture Technologies Corp., Scarsdale, NY) with a compression platen attachment (75 mm dia) using 1 mm/s cross head speed. Textural attributes obtained from TPA such as hardness, adhesiveness, chewiness and springiness which could potentially be correlated with wear behavior. Shredding property of the samples will be assessed by texture analyzer using a grating rig (A/GR) attachment. Results from this test will be presented as work to grate, stiction force, and crumbliness. The test will be conducted at 5°C to mimic the conditions occurring in real processing operations.Cheese wear behavior will be characterized using a tribological Pin in Disk (PID) attachment on an Anton Paar MCR 302 rheometer (Anton Paar, Graz, Austria). Wear will be determined as mass loss as well as penetration depth after applying 1 N tribological force at 50 mm/s sliding speed for 10 min at 5°C. Wear (impression) patterns will be characterized by optical image capture from digital microscope or a digital camera.For making process cheese in objective 1, response surface methodology will be applied to evaluate effect of variables (formulation type i.e. four formulation with varying level of intact casein as defined by their weighted age or three emulsifier levels ) on response variables (wear, shreddability, textural parameters). Additional 6 repetitions will be carried out on a selected formulation to test power of the model. A correlation analysis will be performed for both dependent as well as independent variables. It is hypothesized that variations in intact casein levels and emulsifying salt quantity will be able to produce spectrum of shreddability and textural characteristics. The spectrum of shreddability will then be correlated with measure mechanical properties such as wear behavior and structural characteristics such size of fat particles in cheeses.For objective 2, two set of Mozzarella cheeses (48% moisture, 20% fat, 1.5% salt, pH 5.2) will be made in triplicate in the Utah State University Creamery using 1200 lb of milk in an enclosed vat. One set will have four batches of varying combination of starter cultures; 1. St. thermophilus (lower proteolysis - residual galactose); 2. St. thermophilus and Lb. helveticus (medium proteolysis - residual galactose); 3. St. thermophilus and Lac- Gal+ adjunct culture (lower proteolysis -galactose free); 4. St. thermophilus, Lb. helveticus and Lac- Gal+ adjunct culture (medium proteolysis -galactose free). Second set of cheese samples will be prepared by varying levels of calcium content. This will be attained by renneting milk at two different milk pH levels i.e standard (pH 6.65) and pre-acidified (pH 6.45).Curd will be cooked/stretched using a single screw cooker. These cheeses will then be tested using a variety of methods during seven weeks of storage to see how well the cheese can be shredded, how well it melts and the amount of stretch it retains, as well as baking on a pizza to characterize its browning and blister formation. Apart from rheology, texture and microstructure analysis, these cheeses will be subjected for enumeration of LAB, and NSLAB bacteria, galactose and lactose estimation, evaluation of expressible serum using centrifuge, melt using Schreiber test, flow using temperature sweep, and stretch test using an attachment (extensibility rig) to texture analyzer. Working hypothesis for this work is that performance of mozzarella cheese (melt, stretch and flow) when baked on a pizza can be altered based upon (1) type of starter cultures used which influence extent of residual galactose and proteolytic activity. The residual galactose in the cheese influences the extent to which the cheese browns during baking. (2) calcium content of the cheese by varying pH of cheese milk; calcium mediates protein-protein interactions during stretching of molten cheese curd that forms basis for structure of the mozzarella cheese.For objective 3, we will initially conduct benchmark testing on commercial cream cheese samples. This will help us to determine desirable material characteristics (yield stress, thermo-reversibility of viscoelastic behavior and flow behavior) needed to make product flowable. We would then identify dairy based hydrocolloids or protein-lipid based ingredients to replace traditionally used plant-based hydrocolloids. Rheological behaviors of cream cheese samples obtained from the market will be evaluated under flow conditions experienced during squeezing out using steady shear and to test shelf stability. Cream cheese formulations prepared in the laboratory will be studied for rheological behavior at high-shear (100-200 s-1) and high-heat processing conditions (85-95°C) required for ensuring heat stability of mixed mass of different components. Processing data, (e.g. torque vs. time, viscosity of the molten fluid, rotational speed, and shear power intensity) will be collected and cream cheese rheological parameters, such as yield stress and flow profile, will be estimated from the data. Strain sweeps, frequency sweeps, wear testing, and compressive testing using methods will be conducted on the final samples under conditions as similar as possible to those of oral processing and to those of used for ascertaining shelf life. Hydrocolloid-free formulations of squeezable cream cheese will be prepared by adjusting key processing and formulation factors.Work in objective 3 is based upon the hypothesis that clean label squeezable cream cheese can be developed by (1) manipulating hydrocolloid concentration and type, as it is a key driver of squeezable cream cheese functionality, such as flow behaviors. (2) Modifying both formulations, e.g. replacement of hydrocolloids with dairy proteins and phospholipids, and processing conditions will help develop a novel clean-label squeezable cream cheese product with desirable textural characteristics.Overall, our work will provide theoretical basis whether material properties have impact on functional characteristics of cheeses such as shredding, melting, blistering, oiling off and flow behavior. Understanding relationship between material properties and functionality would be useful in predicting quality of finished product.

Progress 06/29/20 to 06/30/24

Outputs
Target Audience:Target Audience: Target audience for this project is the US cheese manufacturing companies particularly those involved in product development and technical services, cheese converters to minimize their operational losses and maximize their profitability, food science graduates and undergraduate students, partners in BUILD Dairy, Western Dairy Centre. Target audience benefited: The work reported in this project provided useful information to the US cheese manufacturing companies particularly those involved in product development and technical services of Mozzarella and Cheddar cheese. Development of models for predicting sliceability/shreddability index using wear behavior, rheological and textural data offered cheese converters unique perspective to minimize their product losses due to high speed operations. Under the second objective, understanding how calcium content affects the baking performance of Mozzarella cheese. In the third objective we studied cold gelling properties of highly concentrated micellar casein concentrate (HC-MCC). Finding of this work provided useful information to dairy ingredient manufacturing companies such as Idaho Milk Products. Broader public benefited: The work generated from the project activities provided cheese producers and converters to minimize their operational losses and maximize their profitability and improve over sustainability of dairy processing operations. Two post doctoral fellows (Fariba Zad Bagher Seighalani) and Ashutos Parhi, four MS students (Katelynn Palmer, Nathan Pougher, Anjali Verma, Jason Young), five undergrad students (Benjamin Evans, Nathan Pace, Mayank, Sulabh Singh, Sakshi Singh) got trained in this project. Students, post-docs, and visiting scholars gained experience on cheese and dairy product manufacturing and advanced rheological characterization. They were trained in the following techniques: rheology, differential scanning calorimetry, SDS and UREA PAGE, particle size analysis, powder rehydration characteristics, electron microscopy. They also gained experience in the design and execution of experiments and in the analysis and interpretation of the results. Changes/Problems:N/A What opportunities for training and professional development has the project provided?Two post doctoral fellows (Fariba Zad Bagher Seighalani) and Ashutos Parhi, four MS students (Katelynn Palmer, Nathan Pougher, Anjali Verma, Jason Young), five undergrad students (Benjamin Evans, Nathan Pace, Mayank, Sulabh Singh, Sakshi Singh) got trained in this project. Students, post-docs, and visiting scholars gained experience on cheese and dairy product manufacturing and advanced rheological characterization. They were trained in the following techniques: rheology, differential scanning calorimetry, SDS and UREA PAGE, particle size analysis, powder rehydration characteristics, electron microscopy. They also gained experience in the design and execution of experiments and in the analysis and interpretation of the results. Students working on this project have got opportunities to present their work in BUILD dairy annual meeting as well monthly meetings, IDF cheese symposium, ADSA conference, IFT conferences. Several students attended professional development courses organized under BUILD dairy program. Some students, attended basic and advanced cheese making course offered by western dairy center. How have the results been disseminated to communities of interest?Dissemination of the research conducted in this period was disseminated to various communities of the interest through conference presentations, publications of manuscripts. Research Publications: Pace, N.#, Verma, A., Mayank, Parhi, A.*, & Sharma, P. (2023). The utility of a slice defect score method in understanding factors impacting the sliceability of commercial Cheddar cheese blocks. International Dairy Journal, 105865. https://doi.org/10.1016/j.idairyj.2023.105865 (Impact factor: 3.1) Palmer, K.*, Parhi, A., Shetty, A., Sunkesula, V., & Sharma, P. (2023). Development of methodology for assessing flowability of milk protein powders using shear failure testing device. Journal of Food Engineering, 348, 111450. https://doi.org/10.1016/j.jfoodeng.2023.111450 (Impact factor: 7.053) Sharma, P. (2022). ADSA Foundation Scholar Award: Materials science approach to the study of mechanical and diffusion properties in cheese. Journal of Dairy Science, 105 (6), 4711-4721. https://doi.org/10.3168/jds.2021-21093 (Impact factor: 3.5) McMahon, D. J., Sorensen, K. M., Domek, M. J., Dai, X., Sharma, P., Oberg, T. S., & Oberg, C. J. (2022). Gas production by Paucilactobacillus wasatchensis WDCO4 is increased in Cheddar cheese containing sodium gluconate. Journal of Dairy Science, 105(5), 3896-3910. https://doi.org/10.3168/jds.2021-21617 (Impact factor: 3.5) Zad Bagher Seighalani, B., McMahon, D. J., & Sharma, P. (2021). Determination of critical gel-sol transition point of Highly Concentrated Micellar Casein Concentrate using Multiple Waveform Rheological Technique. Food Hydrocolloids, 106886. https://doi.org/10.1016/j.foodhyd.2021.106886 (Impact factor: 10.7) Book chapters McMahon, D. J., Sharma, P., and Oberg, C.J. (2022). Pasta Filata Cheeses: Low-Moisture Part-Skim Mozzarella (Pizza Cheese). In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 262-273). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00201-4 McMahon, D. J., and Sharma, P. (2022). History of Dairy Processing, Technology and Products. In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 671-681). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00254-3 Sharma, P., and Martini, S. (2022). Modified Butters. In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 726-734). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00342-1 Patel H., Sharma, P., and Patel, S. (2022). Milk Protein Concentrate (MPC) and Isolate (MPI). In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 132-140). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00244-0 Sharma, P., and Martini, S. (2022). Milk Fat-Based Spreads. In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 707-714). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00391-3 Sharma, P., and Tong, P. S. (2022). Recombined and Reconstituted Products. In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 463-469). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00392-5 Sharma, P., Sunkesula, V., and Jelen, P. (2022). Standardization of Fat and Protein. In P.L.H. McSweeney and J. P. McNamara (Eds.), Encyclopedia of dairy sciences (3rd Ed., pp 167-173). Academic Press. https://doi.org/10.1016/B978-0-12-818766-1.00394-9 Conference presentations: Young JD*, Vollmer AH, McMahon DJ, and Sharma P (2023). Impact of emulsifying salt and intact casein levels on wear behavior, microstructure, and shredding performance of process cheese. 9th International Symposium of Food Rheology and Structure, Wageningen, The Netherlands, Switzerland, June 11-15. (Invited talk) Pougher N* and Sharma P (2022). Effect of calcium chelating salts on cold gelation behavior of highly concentrated micellar casein concentrate. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Poster presentation) Verma A*, McMahon D, and Sharma P (2023). Effect of calcium content on unmelted texture and pizza baking properties of mozzarella cheese. IFT FIRST Annual Event and Expo, July 16 - 17, 2023, Chicago, Illinois. (Finalist in Manfred Oral Competition and won third prize) Pougher N*, Vollmer A, and Sharma P (2023). Understanding the Mechanism of Cold Gel Formation in Highly Concentrated-Micellar Casein Concentrate (HC-MCC) Solutions: Impact of Calcium Chelation and pH Adjustment. 9th International Symposium of Food Rheology and Structure, Wageningen, The Netherlands, Switzerland, June 11-15. (Poster) Pougher N*, and Sharma P (2022). Effect of varying pH on the cold gelling behavior of highly concentrated micellar casein concentrate (HC-MCC). American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Abstract no. 1200). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 77. (Oral presentation). Palmer K*, Parhi A*, Thakur S*, Shetty A, Sunkesula V, and Sharma P (2023). Impact of Moisture Content and Particle Size on the Flow Characteristics of Milk Protein Isolate 90. IFT FIRST Annual Event and Expo, July 16 - 17, 2023, Chicago, Illinois. (Poster presentation) Sharma P, Palmer K* and Parhi A* (2022). Improving sustainability during production & storage of food powder systems. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Invited Oral) Pougher N* and Sharma P (2022). Effect of calcium chelating salts on cold gelation behavior of highly concentrated micellar casein concentrate. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Poster presentation) Palmer K*, Parhi A*, Shetty A, Sunkesula V and Sharma P (2022). Flow behavior of milk protein powders using shear cell methodology. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Oral presentation) Anjali F*, McMahon DJ, Oberg TS and Sharma P (2022). Effect of galactose utilization and proteolytic activity of adjunct cultures on viscoelastic and textural properties of Mozzarella cheese. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Oral presentation) Pace N#, Parhi A*, and Sharma P. (2022). Assessing the impact of storage time and shape of the block on the slicability of commercial cheddar cheese. American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Abstract no. 1023). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 9. (Oral presentation) Anjali F*, McMahon DJ, Oberg TS and Sharma P (2022). Effect of galactose-utilizing bacteria on pizza-baking properties of Mozzarella cheese. American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Abstract no. 1137). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 52. (Oral presentation) Pougher N*, and Sharma P (2022). Effect of varying pH on the cold gelling behavior of highly concentrated micellar casein concentrate (HC-MCC). American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Abstract no. 1200). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 77. (Oral presentation). Palmer K*, Parhi A, Shetty A, Sunkesula V and Sharma P (2022). Characterizing flow behavior of milk protein powders using shear cell methodology. American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Abstract no. 1006). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 3. (Oral presentation) Young JD*, Vollmer AH, McMahon DJ, Sharma P (2021). Effect of emulsifying salt, and age of natural cheese on microstructure, wear behavior and grating properties of process cheese. American Dairy Science Association virtual annual meeting, USA, July 11-14, 2021. (Oral presentation, Abstract no. 215). What do you plan to do during the next reporting period to accomplish the goals?N/A

Impacts
What was accomplished under these goals? Objective 1 Determining material properties useful in predicting shreddability of cheeses The effects of process cheese formulation on microstructure, material, and rheological properties of process cheese were investigated to determine the usefulness of wear behavior in predicting cheese shreddability. Experimental process cheese formulations were made with varying levels (2.0, 2.5, 3.0%) of trisodium citrate (TSC) and varying average ages (1, 22, 83, 102 d) of natural cheese (varying levels of intact casein) to create a spectrum of shreddability, material behaviors, and rheological properties for use in shreddability modeling. A modified full factorial design with 12 formulations and 3 replicates on each of the 2 central points was used to study the effect of treatments. Electron micrographs of process cheese indicated that size of fat globules decreased with increasing of both age of natural cheese and TSC concentration. Age of process cheese formulation had a significant (p < 0.01) positive correlation with penetration depth (mm) and mass loss (g). With increasing of natural cheese age, G* values (at 0.01% strain) decreased significantly (p < 0.01), and G' (at 0.01% strain) decreased (p < 0.01). Process cheese formulation age had a significant (p < 0.01) positive correlation with work to grate and negative correlation with crumbliness. A shreddability index (SI) was developed using sieve data for the process cheese samples. Significant correlations (p < 0.05) were found between tribological (wear), rheological and material properties and the SI. Of the models tested, variables from wear tests (mass loss and penetration depth) were able to account for much of the variation in shredding behavior ( r= 0.74, p < 0.01). It is therefore determined that wear tests are an effective tool in predictive models of process cheese shreddability. It was concluded for sliceability experiments that the quality of cheddar cheese in terms of slicing characteristics improved throughout the experiment as storage time increased. This is due to enzyme breakdown, pH change, and bacterial count. In order to understand these results more, further research will be conducted and reviewed to see if they complement one another. Tests such as moisture content, wear tribology, and extensibility will help determine the cheeses attributes. The data extracted from all these experiments will be compiled into an index report and compared with existing data. Objective 2a (Determine influence of proteolysis and residual galactose in cheese based on type of cultures used on textural, melting and baking properties of mozzarella cheese) Cheese making: Mozzarella cheese (48% moisture, 25% fat, 1.5% salt, pH 5.2) was manufactured using method described by McMahon et al. (1999) using 1200 lb milk with four starter culture combinations in triplicate: A. St. thermophilus (lower proteolysis - residual galactose); B. St. thermophilus and Lb. helveticus (medium proteolysis - residual galactose); C. St. thermophilus and Lac- Gal+ adjunct culture (lower proteolysis -galactose free); D. St. thermophilus, Lb. helveticus and Lac- Gal+ adjunct culture (medium proteolysis -galactose free) Curd before salting and afterwards was sampled and analyzed for various characterisrtics. Browning and blistering ability of Mozzarella cheese were generally not affected by the lactose and galactose utilizing ability of starter cultures to a great extent. Although, galactose content of cheese samples made with galactose- fermenting culture declined during ageing. The galactose level in sample D (containing gal + lac - culture) were significantly lower than sample A (containing lac+ and gal- culture) after 14 days ageing. A further decrease in galactose was not observed which could be a result of decline in desirable activity of starter culture during ageing i.e., the culture was surviving but was not metabolically active. Also, in our study all samples reported high initial lactose content (1-1.2%), resulting in excess of available lactose which inhibited the gal+ culture to use galactose. Along with residual sugars, browning reaction is also affected by the breakdown products of proteolysis like peptides and amino groups. Advancing proteolysis during ageing overcame the effect of galactose reduction which caused similar browning and blistering in all baked pizzas. Applying reduced galactose treatment for low-moisture mozzarella cheese making will improve baking and melting profile, and slightly lower browning during pizza baking. Objective 2b Determine influence of calcium content on textural, melting and baking properties of mozzarella cheese In this objective, we investigated the effect of whey drain pH on the molten texture and baking performance of Mozzarella cheese on pizza baking. Mozzarella cheese with three drain pH levels (6.4, 6.0, and 5.6) was prepared in the pilot facility of USU. Melting, texture, and baking properties of Mozzarella cheese were evaluated over seven weeks. Drawing whey at three pH levels yielded samples with different amounts of INSOL Ca linked with protein. Samples with pH 6.4 had 16.6% higher calcium content than the sample with 5.6 pH. Samples drained at pH 6.4 (high calcium) exhibited increased hardness, reduced free oil release, and decreased melting (p<0.05). Cheese samples with drain pH 5.4 (low calcium) demonstrated 32% less blistering and 56% smaller blister size on baked pizza at 2 weeks timepoint and similar trend was observed at 4 weeks as well. In the early stage of ageing, the effect whey drain pH or INSOL Ca in cheese matrix was clearly visible, however at the end of 7 weeks the treatment effect was overtaken by the proteolytic activity. All samples displayed an increase in melting (LTmax), loss in hardness, because of the gradual proteolysis that occurred during storage. Low calcium content resulted in weaker in protein-protein interactions causing softer body, increased melting and free oil, and therefore reduced browning and blistering. Our findings emphasize that browning and blistering in Mozzarella cheese can be controlled just by manipulating INSOL Ca linked with protein through draining the whey at different pH levels. In objective 3, Rheological tests were conducted to observe the sol-gel transition point of HC-MCC by conducting temperature sweeps on MCR302 rheometer using a multiple waveform technique with application of Winter-Chambon criteria. This criterion is considered more accurate than the traditional crossover point of G" and G', as it relies on the convergence of the loss factor at multiple frequencies to determine the true gelation point. These tests were performed in combination with time and temperature sweeps. Additionally, HC-MCC samples were modified by diluting to a minimum protein content where gelation still occurred. This formed the basis for observing changes in cold gel temperature at varying pH (5.8-6.6) by adding glucono-delta-lactone. The minimum protein concentration which could form a cold gel was determined to be 16.8%, which was then used to observe the effects of pH modifications. Addition of the acid i.e. drop in pH increased the temperature of gel-sol transition, and increased storage modulus values for low pH samples. Additionally, acidified samples continued to behave as viscoelastic liquids at elevated temperatures and viscoelastic solid at low temperatures indicating thermoreversibility of cold gels. Overall, this study explored the possibility of modifying HC-MCC to utilize it in the future as a dairy based thickener or stabilizer. Adding a dairy based stabilizer to another dairy product could improve consumer preferability rather than using polysaccharide-based gums for similar purposes.

Publications


    Progress 10/01/22 to 09/30/23

    Outputs
    Target Audience:Target Audience: The work reported in this period will be of interest to US cheese manufacturing companies particularly those involved in product development and technical services of Mozzarella and Cheddar cheese. The main focus of this work was to develop understanding about sliceability/shreddability of cheese under objective 1. We want to develop a models for predicting sliceability/shreddability index using wear behavior, rheological and textural data. This will help cheese converters to minimize their product losses due to high speed operations. Under the second objective, in this reporting period we studied how calcium content affects the baking performance of Mozzarella cheese. The findings from this work will help cheese producers and converters to minimize their operational losses and maximize their profitability. The target groups i.e.. cheese manufacturing companies in the intermountain region, will be approached through BUILD dairy network. In the third objective we studied cold gelling properties of highly concentrated micellar casein concentrate (HC-MCC). Finding of this work will help dairy ingredient manufacturing companies such as Idaho Milk Products. Changes/Problems:None to report for this period. What opportunities for training and professional development has the project provided?Two grads (Anjali, Nathan Pougher) and one undergrad (Nathan Pace) student worked on this project who got opportunity to present their data in the various national and international conferences including American Dairy Science Association, Institute of Food Technologists, and International Symposia of Food structure and rheology, BUILD Dairy annual conference and monthly meetings. Anjali Verma participated in the IFT Dairy Food Division students Oral competition and won third place in the competition. Nathan Pace participated in the under grads student research competition in the annual ADSA conference, held in Ottawa, Canada. Nathan Pougher got placed to work as product development specialist in the TreeTop, WA. And Anjali got placement in the Idaho Milk Products. How have the results been disseminated to communities of interest?Dissemination of the research conducted in this period was disseminated to various communities of the interest through conference presentations, publications of manuscripts. Publications: Pace, N.#, Verma, A., Mayank, Parhi, A.*, & Sharma, P. (2023). The utility of a slice defect score method in understanding factors impacting the sliceability of commercial Cheddar cheese blocks. International Dairy Journal, 105865. https://doi.org/10.1016/j.idairyj.2023.105865 (Impact factor: 3.1) Palmer, K.*, Parhi, A., Shetty, A., Sunkesula, V., & Sharma, P. (2023). Development of methodology for assessing flowability of milk protein powders using shear failure testing device. Journal of Food Engineering, 348, 111450. https://doi.org/10.1016/j.jfoodeng.2023.111450 (Impact factor: 7.053) Sharma, P. (2022). ADSA Foundation Scholar Award: Materials science approach to the study of mechanical and diffusion properties in cheese. Journal of Dairy Science, 105 (6), 4711-4721. https://doi.org/10.3168/jds.2021-21093 (Impact factor: 3.5) Conference presentations: Young JD*, Vollmer AH, McMahon DJ, and Sharma P (2023). Impact of emulsifying salt and intact casein levels on wear behavior, microstructure, and shredding performance of process cheese. 9th International Symposium of Food Rheology and Structure, Wageningen, The Netherlands, Switzerland, June 11-15. (Invited talk) Pougher N* and Sharma P (2022). Effect of calcium chelating salts on cold gelation behavior of highly concentrated micellar casein concentrate. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Poster presentation) Verma A*, McMahon D, and Sharma P (2023). Effect of calcium content on unmelted texture and pizza baking properties of mozzarella cheese. IFT FIRST Annual Event and Expo, July 16 - 17, 2023, Chicago, Illinois. (Finalist in Manfred Oral Competition and won third prize) Pougher N*, Vollmer A, and Sharma P (2023). Understanding the Mechanism of Cold Gel Formation in Highly Concentrated-Micellar Casein Concentrate (HC-MCC) Solutions: Impact of Calcium Chelation and pH Adjustment. 9th International Symposium of Food Rheology and Structure, Wageningen, The Netherlands, Switzerland, June 11-15. (Poster) Pougher N*, and Sharma P (2022). Effect of varying pH on the cold gelling behavior of highly concentrated micellar casein concentrate (HC-MCC). American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Abstract no. 1200). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 77. (Oral presentation). Nathan Pougher and Anjali Verma also presented their work in the BUILD dairy conference attended by industry personnel and some dairy farmers. What do you plan to do during the next reporting period to accomplish the goals?Objective 2. Next step is to compile all the data and publish in the reputed scientific journal. Objective 3. MCC samples will evaluated for their cold gelling properties by manipulating pH and calcium chelation tendency. This work will help in understanding mechanism of cold gel formation.

    Impacts
    What was accomplished under these goals? In this reporting period main emphasis was on objective 2 (Understanding factors influencing melt, hot flow, stretchability and baking performance of cheeses) and 3 (studying rheological behavior and manipulating of cold gelling point of highly concentrated micellar casein concentrate ). Objective 2b (Determine influence of calcium content on textural, melting and baking properties of mozzarella cheese) was completed. In this period, we investigated the effect of whey drain pH on the molten texture and baking performance of Mozzarella cheese on pizza baking. We hypothesize that low drain pH will lead to lower amount of calcium associated with caseins (INSOL Ca), which will cause increase in melting and free oil release, thereby, reducing browning and blistering on pizza. Mozzarella cheese with three drain pH levels (6.4, 6.0, and 5.6) was prepared in the pilot facility of USU. Melting, texture, and baking properties of Mozzarella cheese were evaluated over seven weeks. Temperature sweeps (20°C-90°C) were conducted on an MCR-302 rheometer for studying changes in viscoelastic properties (G', G" and LTmax) of cheese during melting. Free oil release was quantified using modified Babcock method. Pizza was baked at 260°C for 6 minutes in an air impinger convection oven and image-analysis was conducted for quantifying browning and blistering. Drawing whey at three pH levels yielded samples with different amount of INSOL Ca linked with protein. Samples with pH 6.4 had 16.6% higher calcium content than the sample with 5.6 pH. Samples drained at pH 6.4 (high calcium) exhibited increased hardness, reduced free oil release, and decreased melting (p<0.05). Cheese samples with drain pH 5.4 (low calcium) demonstrated 32% less blistering and 56% smaller blister size on baked pizza at 2 weeks timepoint and similar trend was observed at 4 weeks as well. In the early stage of ageing, the effect whey drain pH or INSOL Ca in cheese matrix was clearly visible, however at the end of 7 weeks the treatment effect was overtaken by the proteolytic activity. All samples displayed an increase in melting (LTmax), loss in hardness, because of the gradual proteolysis that occurred during storage. Low calcium content resulted in weaker in protein-protein interactions causing softer body, increased melting and free oil, and therefore reduced browning and blistering. Our findings emphasize that browning and blistering in Mozzarella cheese can be controlled just by manipulating INSOL Ca linked with protein through draining the whey at different pH levels. In objective 3, Rheological tests were conducted to observe the sol-gel transition point of HC-MCC by conducting temperature sweeps on MCR302 rheometer using a multiple waveform technique with application of Winter-Chambon criteria. This criteria is considered more accurate than the traditional crossover point of G" and G', as it relies on the convergence of the loss factor at multiple frequencies to determine the true gelation point. These tests were performed in combination with time and temperature sweeps. Additionally, HC-MCC samples were modified by diluting to a minimum protein content where gelation still occurred. This formed the basis for observing changes in cold gel temperature at varying pH (5.8-6.6) by adding glucono-delta-lactone. The minimum protein concentration which could form a cold gel was determined to be 16.8%, which was then used to observe the effects of pH modifications. Addition of the acid i.e. drop in pH increased the temperature of gel-sol transition, and increased storage modulus values for low pH samples. Additionally, acidified samples continued to behave as viscoelastic liquids at elevated temperatures and viscoelastic solid at low temperatures indicating thermoreversibility of cold gels. Overall, this study explored the possibility of modifying HC-MCC to utilize it in the future as a dairy based thickener or stabilizer. Adding a dairy based stabilizer to another dairy product could improve consumer preferability rather than using polysaccharide-based gums for similar purposes.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2023 Citation: Pace, N., Verma, A., Parhi, A., & Sharma, P. (2023, December 22). The utility of a slice defect score method in understanding factors impacting the sliceability of commercial Cheddar cheese blocks. International Dairy Journal.
    • Type: Journal Articles Status: Published Year Published: 2023 Citation: Palmer, K., Parhi, A., Shetty, A., Sunkesula, V., & Sharma, P. (2023, February 06). Development of methodology for assessing flowability of milk protein powders using shear failure testing device. Journal of Food Engineering, 348.


    Progress 10/01/21 to 09/30/22

    Outputs
    Target Audience:The work reported in this period will be of interest to US cheese manufacturing companies particularly those involved in product development and technical services of Mozzarella and Cheddar cheese. The main focus of this work was to develop understanding about sliceability of cheese under objective 1. We want to develop a models for predicting sliceability index using wear behavior, rheological and textural data. This will help cheese converters to minimize their product losses due to high speed operations. Under the second objective, we studied baking performance of Mozzarella cheese as influenced by calcium content and residual lactose. The findings from this work will help cheese producers and converters to minimize their operational losses and maximize their profitability. The target groups ie.. cheese manufacturing companies in the intermountain region, will be approached through BUILD dairy network. Changes/Problems:There was an initial delay in the start of objective 2 because a Graduate student (Isaac Martineau) decided to leave the program in the model. This has put a hold on the objective 2 until I found a replacement for him. Because of Covid 19 situation, it was not easy to find a suitable student. This caused at least six months delay in the project. Our first trial was not successful which needs to repeated. Further PI got stuck in India during April, May 2021 due to Covid 19 situation, this also significantly impacted the plan. In objective 3. Cream cheese was replaced with MCC samples for studying rheological behavior and manipulating of cold gelling point of highly concentrated micellar casein concentrate for its potential use in clean label dairy products. What opportunities for training and professional development has the project provided?Two grads (Anjali, Nathan Pougher) and one undergrad (Nathan Pace) student working on this project got opportunity to present their data in the various national and international conferences including American Dairy Science Association, Institute of Food Technologists, and International Dairy Federation Cheese symposium, BUILD Dairy annual conference and monthly meetings. Couple of students attended basic and advanced short cheese making courses offered by Western Dairy Center. Nathan Pougher and Anjali participated in the Idaho Milk Processors Association (IMPA) product develop competition and won third place. How have the results been disseminated to communities of interest?Graduate students presented their work at various conferences. F. Anjali*, D. J. McMahon, T. S. Oberg, and P. Sharma. Effect of galactose-utilizing bacteria on pizza-baking properties of Mozzarella cheese. J. Dairy Sci. Vol. 105, Suppl. 1:52. Sharma, P. (2022). ADSA Foundation Scholar Award: Materials science approach to the study of mechanical and diffusion properties in cheese. Journal of Dairy Science, 105 (6), 4711-4721. https://doi.org/10.3168/jds.2021-21093 McMahon, D. J., Sorensen, K. M., Domek, M. J., Dai, X., Sharma, P., Oberg, T. S., & Oberg, C. J. (2022). Gas production by Paucilactobacillus wasatchensis WDCO4 is increased in Cheddar cheese containing sodium gluconate. Journal of Dairy Science, 105(5), 3896-3910. https://doi.org/10.3168/jds.2021-21617 Zad Bagher Seighalani, B., McMahon, D. J., & Sharma, P. (2021). Determination of critical gel-sol transition point of Highly Concentrated Micellar Casein Concentrate using Multiple Waveform Rheological Technique. Food Hydrocolloids, 106886. https://doi.org/10.1016/j.foodhyd.2021.106886 Pougher N and Sharma P (2022). Effect of calcium chelating salts on cold gelation behavior of highly concentrated micellar casein concentrate. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Poster) Anjali F, McMahon DJ, Oberg TS and Sharma P (2022). Effect of galactose utilization and proteolytic activity of adjunct cultures on viscoelastic and textural properties of Mozzarella cheese. IFT FIRST Annual Event and Expo, July 10 - 13, 2022, Chicago, Illinois. (Oral) Pougher N, and Sharma P (2022). Effect of varying pH on the cold gelling behavior of highly concentrated micellar casein concentrate (HC-MCC). American Dairy Science Association virtual annual meeting, Kanas City, MO June 19-22, 2022. (Oral presentation, Abstract no. 1200). Abstract published in Journal of Dairy Science, 105 (Suppl 1), 77. What do you plan to do during the next reporting period to accomplish the goals?Objective 1. Next step is to develop a comprehensive sliceability index for Cheddar type cheese which can potentially be utilized for prediction using machine machine learning tools to improve predictability of shreddability index using rheology, texture and wear data. This will include developing first baseline data, followed by full scale cheese making experiments. Objective 2b. Testing on Mozzarella cheese prepared for this objective will be completed. Data analysis and manuscript will be prepared on the determination of impact of calcium levels on the baking properties of mozzarella cheese. Objective 3. Cream cheese was replaced with MCC samples for studying rheological behavior and manipulating of cold gelling point of highly concentrated micellar casein concentrate for its potential use in clean label dairy products.

    Impacts
    What was accomplished under these goals? In this reporting period, proposed work in objective 1 (Determining material properties useful in predicting sliceability of cheeses) was initiated. more emphasis was given on understanding sliceability of commercial samples. In this study, the thicknesses chosen for this experiment were based off the retail standard and then in increments of 0.5mm. The storage period times were chosen to be conducted on a weekly basis over a five-week period. Triangles and squares were chosen for shapes in this experiment because triangles are most commonly used in fast food chains and squares are found in retail stores to be purchased by consumers. Lastly, the cheese types of cheddar used in this experiment were mild, medium, sharp, and extra sharp. The cheese slices improved in quality over the storage period. The average score for 0.5 mm on day zero was 4.21 while the average score for 1.0 mm was 3.00 while the average for 1.5 mm was 2.96. The 2.0 mm had the best score on day zero with a starting score of 2.79. The average scores at the end of the experiment on day thirty-five demonstrated that they all improved. The 0.5 mm slices showed an improvement of 2.80, which was higher than the other samples. Concurrently, the 1.0 mm went to 2.30 while the 1.5 mm slices improved to a score of 2.17. Finally, the averages for 2.0 mm on day thirty-five were 2.04. These numbers are taken from the results of the experiment that are displayed in figures 1-8.From these averages the slices cut at 0.5 mm had the most improvement while those cut at 2.0 mm received the best scores at both the start and the end. With the two middle thicknesses falling in the middle in accordance with their corresponding thicknesses. A trend was seen that the square samples tended to receive a better score over the triangular shape. This is believed to be due to the corner pressure angle stress the samples received. The square samples had four corners of 90 degrees. Triangular samples contained one 90-degree corner and two with 45 degrees. These smaller angles wouldn't have been able to handle the stress and pressure of the slicing as well and would've been more prone to defects. It was noted that while the cheese sliced at 0.5 mm were the most improved, they often had the most inconsistent results throughout the experiment which is believed to be from moisture loss and an increased chance of defect. While the thicker samples followed a general change to a better score, the 0.5mm slices tended to reach the same concussion but took a more variant way. It is concluded that the quality of cheddar cheese in terms of slicing characteristics improved throughout the experiment as storage time increased. This is due to enzyme breakdown, pH change, and bacterial count. In order to understand these results more, further research will be conducted and reviewed to see if they complement one another. Tests such as moisture content, wear tribology, and extensibility will help determine the cheeses attributes. The data extracted from all these experiments will be compiled into an index report and compared with existing data. After initial setback in the objective 2, because of a student leaving in the middle, objective 2a (Determine influence of proteolysis and residual galactose in cheese based on type of cultures used on textural, melting and baking properties of mozzarella cheese) was successfully completed. Four replicates of the cheese trial with following details were accomplished. Cheese making: Mozzarella cheese (48% moisture, 25% fat, 1.5% salt, pH 5.2) was manufactured using method described by McMahon et al. (1999) using 1200 lb milk with four starter culture combinations in triplicate: A. St. thermophilus (lower proteolysis - residual galactose); B. St. thermophilus and Lb. helveticus (medium proteolysis - residual galactose); C. St. thermophilus and Lac- Gal+ adjunct culture (lower proteolysis -galactose free); D. St. thermophilus, Lb. helveticus and Lac- Gal+ adjunct culture (medium proteolysis -galactose free) Curd before salting and afterwards will sampled and analyzed for: Bacteria growth was assessed: on M17L and MRS agars. Lactose and Galactose content (on frozen cheese samples) was determined using Megazyme kits. Cooker/stretcher temperatures of 70°C (cheese 55-60°C). Browning and blistering ability of Mozzarella cheese were generally not affected by the lactose and galactose utilizing ability of starter cultures to a great extent. Although, galactose content of cheese samples made with galactose- fermenting culture declined during ageing. Galactose level in sample D (containing gal + lac - culture) were significantly lower than sample A (containing lac+ and gal- culture) after 14 days ageing. Further decrease in galactose was not observed which could be a result of decline in desirable activity of starter culture during ageing i.e., the culture was surviving but was not metabolically active. Also, in our study all samples reported high initial lactose content (1-1.2%), resulting in excess of available lactose which inhibited the gal+ culture to use galactose. Along with residual sugars, browning reaction is also affected by the breakdown products of proteolysis like peptides and amino groups. Advancing proteolysis during ageing overcame the effect of galactose reduction which caused similar browning and blistering in all baked pizzas. Applying reduced galactose treatment for low-moisture mozzarella cheese making will improve baking and melting profile, and slightly lower browning during pizza baking. Work on Objective 2b has been initiated which involves understanding impact of calcium content on baking performance of Mozzarella cheese. Two set of cheese making experiments were successfully completed. Cheese samples with three different draw pH were prepared in the GHR Dairy Product Lab at Utah State University. Samples were drained at 6.4, 6.0, and 5.6 respectively which will result in varying amount of calcium in cheese samples. Sample with highest drain pH will result in high amount of calcium content. Mozzarella cheese (46 - 48% moisture, 23 - 25% fat, 1.5% salt, pH 5.3) was manufactured using 1200 lb. milk with four starter culture combinations: All the samples are now being assessed for compositional, rheological, textural, and baking properties as described in objective 2a. Studies on cold gelling experiment using highly-concentrated MCC are also underway and will be reported in the next report.

    Publications

    • Type: Journal Articles Status: Published Year Published: 2022 Citation: Sharma, P. (2022, June 01). ADSA Foundation Scholar Award: Materials science approach to the study of mechanical and diffusion properties in cheese. Journal of Dairy Science, 105(6), 4711-4721.


    Progress 10/01/20 to 09/30/21

    Outputs
    Target Audience:The work reported in this period will be of interest to US cheese manufacturing companies particularly those involved in product development and technical services of Mozzarella and process cheese. The main focus of this work was to develop shreddability index on the process cheese samples produced in reporting period 2020-21 and predict the shreddability index using wear behavior and textural properties. The second objective was to study baking performance of Mozzarella cheese as influenced by varying proteolytic and galactose utilizing ability of starter cultures. The findings from this work will help cheese producers and converters to minimize their operational losses and maximize their profitability. The target groups ie.. cheese manufacturing companies, will be approached through BUILD dairy network. Changes/Problems:We hired a graduate student (Isaac Martineau) to work on objective 2 involving impact of proteolysis and galactose utilization on baking performance of Mozzarella cheese. But he decided to leave his graduate program after finishing one semester. This has put a hold on that objective until we find a replacement for him. This caused at least six month delay in the project. Our first trial was not successful which needs to repeated. What opportunities for training and professional development has the project provided?Graduate students (Jason Young and Anjali) working on this project have got opportunities to present their work in BUILD dairy annual meeting as well monthly meetings, IDF cheese symposium, ADSA conference. Jason Young also attended professional development courses organized under BUILD dairy program. He successfully his thesis and awarded master's degree. Anjali, attended basic and advanced cheese making course offered by western dairy center. Benjmain Evan and Weston, undergrad students presented their work to the larger interdisciplinary group. How have the results been disseminated to communities of interest?Jason Young, graduate student completed his master's thesis on "Wear Behaviors of Process Cheese with Varying Formulations and the Development of Predictive Models on Shreddability" which is available online at https://digitalcommons.usu.edu/etd/8263; Jason Young presented his work on wear behavior and Anjali presented her work on Mozzarella cheese at the BUILD dairy annual meeting organized at Boise State University, during September 7-9, 2021. The meeting was attended by the dairy industry professionals, professors, and students. Oral presentations from Jason Young's work were made in ADSA, IDF Cheese symposium and IFT conferences organized in the summer 2021. What do you plan to do during the next reporting period to accomplish the goals?Objective 1. Next step is to utilize learnings from wear behavior of process cheese and apply them on natural cheeses such as cheddar cheese, develop predictive models on sliceability of cheddar cheese, use machine machine learning tools to improve predictability of shreddability index using rheology, texture and wear data. Objective 2a. Testing on third replicate of Mozzarella cheese will be completed. Fourth replicate will prepared using combination of selected starter cultures. Data analysis and manuscript will prepared on the determination of impact of proteolysis and residual galactose in cheese based on type of cultures used on textural, melting and baking properties of mozzarella cheese. Objective 2b. Impact of calcium content on baking performance of Mozzarella cheese will be studies. Standard Mozzarella cheese (with Streptococcus thermophilus) will be prepared at three drain pH level. Samples will be tested for rheology, texture, shreddability, lactose and galactose, etc. It is proposed that in Objective 3. cream cheese may be replaced with MCC samples for studying rheological behavior and manipulating of cold gelling point of highly concentrated micellar casein concentrate for its potential use in clean label dairy products.

    Impacts
    What was accomplished under these goals? In this reporting period, proposed work in objective 1 (Determining material properties useful in predicting shreddability of cheeses) was completed. more emphasis was given on developing shreddability index for the process cheese samples produced from the last reporting period (2020-21) by varying intact casein levels and emulsifying salt concentration. Process cheese was used as a model system as it is more stable and robust as compared to natural cheeses. The effects of process cheese formulation on microstructure, material, and rheological properties of process cheese were investigated to determine the usefulness of wear behavior in predicting cheese shreddability. Experimental process cheese formulations were made with varying levels (2.0, 2.5, 3.0%) of trisodium citrate (TSC) and varying average ages (1, 22, 83, 102 d) of natural cheese (varying levels of intact casein) to create a spectrum of shreddability, material behaviors, and rheological properties for use in shreddability modeling. A modified full factorial design with 12 formulations and 3 replicates on each of the 2 central points was used to study effect of treatments. Microstructure of process cheese samples was characterized using confocal laser scanning microscopy and transmission electron microscopy. Micrographs of process cheese indicated that size of fat globules decreased with increasing of both age of natural cheese and TSC concentration. Wear behavior for process cheese was determined using a pin-on-disk tribological attachment at sliding velocity of 50 mm/s, 5°C, and 1 N normal force. Age of natural cheese had a significant (p < 0.01) positive correlation with penetration depth (mm) and mass loss (g). Rheological characterizations of all samples were performed at 5°C using large and small amplitude oscillatory shear tests. With increasing of natural cheese age, G* values (at 0.01% strain) decreased significantly (p < 0.01), and G' (at 0.01% strain) decreased (p < 0.01). Texture Profile Analysis performed at 25% compression, 1 mm/s, and 5°C showed that natural cheese age had a significant (p < 0.01) negative correlation with gumminess and hardness. Shreddability tests were performed on the Texture Analyzer with a grating rig attachment at 5°C and 15 mm/s sliding speed with 2 kg force. Natural cheese age had a significant (p < 0.01) positive correlation with work to grate and negative correlation with crumbliness. A shreddability index (SI) was developed using sieve data for the process cheese samples. Significant correlations (p < 0.05) were found between tribological (wear), rheological and material properties and the SI. Predictive models were created from this correlation. Of the models tested, variables from wear tests (mass loss and penetration depth) were able to account for much of the variation in shredding behavior ( = 0.74, p < 0.01). It is therefore determined that wear tests are an effective tool in predictive models of process cheese shreddability. Though the work on objective 2 got a bit delayed due to one of graduate student decided to leave the program in the middle and It took a while to get a replacement student, significant amount of work was conducted in objective 2a (Determine influence of proteolysis and residual galactose in cheese based on type of cultures used on textural, melting and baking properties of mozzarella cheese). Cheese making: Mozzarella cheese (48% moisture, 25% fat, 1.5% salt, pH 5.2) was manufactured using method described by McMahon et al. (1999) using 1200 lb milk with four starter culture combinations in triplicate: St. thermophilus (lower proteolysis - residual galactose)St. thermophilus and Lb. helveticus (medium proteolysis - residual galactose)St. thermophilus and Lac- Gal+ adjunct culture (lower proteolysis -galactose free)St. thermophilus, Lb. helveticus and Lac- Gal+ adjunct culture (medium proteolysis -galactose free) Curd before salting and afterwards will sampled and analyzed for: Bacteria growth was assessed: on M17L and MRS agars. Lactose and Galactose content (on frozen cheese samples) was determined using Megazyme kits. Cooker/stretcher temperatures of 70°C (cheese 55-60°C). After 2, 4 and 7 weeks of refrigerated storage the cheese was evaluated for Shreddability using Texture analyzer (special attachment), Hardness, Springiness, Adhesiveness using Texture Profile analysis, Stretchability using Texture analyzer (special attachment) (using method described by To et al., 2020) Meltability using rheometer (temperature ramp), Expressible moisture using centrifuge (using method described by McMahon et al., 1999 and Guo & Kindstedt (1995), Free oil by expression upon heating (Kindstedt & Rippe, 1990), Melt test by Schreiber melt test (Sharma et al., 2015), Baking performance on pizza in Impinger convection oven Visual appearance of shred fusion and oiling blistering and browning (Image analysis) (Ma et al., 2013) Fork stretch test (Moyes, 2003), St. thermophilus and lactobacilli number by plate counts on M17L and MRS at 2 weeks. (Ortakci et al., 2016)Lactose and galactose using an enzyme kit ( Megazyme Lactose & D-Galactose Assay Procedure; Megazyme, Bray, Ireland) depending on availability of equipment. Testing on two replicates is already accomplished. Testing on third replicate is in progress. Because of inherent variations in cheese making, we are planning on making fourth replicate to study the impact of galactose utilization of pizza baking.

    Publications

    • Type: Book Chapters Status: Published Year Published: 2021 Citation: Book Chapters McMahon, D. J., & Sharma, P. (2021). History of Dairy Processing, Technology and Products. Encyclopedia of Dairy Sciences, 3rd edition. Elsevier
    • Type: Book Chapters Status: Published Year Published: 2021 Citation: McMahon, D. J., Sharma, P., & Oberg, C. J. (2021). CHEESE: Pasta-Filata Cheeses: Low-Moisture Part-Skim Mozzarella (Pizza Cheese). Encyclopedia of Dairy Sciences, 3rd edition. Elsevier 1206
    • Type: Journal Articles Status: Published Year Published: 2021 Citation: Zad Bagher Seighalani, F., McMahon, D. J., & Sharma, P. (2021, May 13). Determinization of critical gel-sol transition temperature of Highly Concentrated Micellar Casein Concentrate gels using Multiple Waveform Rheological Technique. Food Hydrocolloids.
    • Type: Conference Papers and Presentations Status: Other Year Published: 2021 Citation: Presentations Sharma, P. (Presenter & Author), 2021 Global Cheese Technology Forum, "Studying salt diffusion in cheese matrices using novel techniques," ADPI, Virtual. (October 27, 2021 - October 29, 2021)
    • Type: Conference Papers and Presentations Status: Other Year Published: 2021 Citation: Presentations Zad Bagher Seighalani, F. (Author Only), Sharma, P. (Presenter & Author), 2021 American Dairy Science Association (ADSA) Annual Meeting, "A novel method of determining critical gel-sol transition point of micellar casein concentrate using multiple waveform rheological technique," ADSA, Virtual. (July 11, 2021 - July 14, 2021)
    • Type: Conference Papers and Presentations Status: Other Year Published: 2021 Citation: Presentations Sharma, P. (Presenter & Author), 2021 American Dairy Science Association (ADSA) Annual Meeting, "ADSA Foundation scholar award lecture: Can material science approaches solve dairy industry problems?," ADSA, Virtual. (July 11, 2021 - July 14, 2021)
    • Type: Conference Papers and Presentations Status: Other Year Published: 2021 Citation: Presentations Young, J. D. (Author Only), McMahon, D. J. (Author Only), Sharma, P. (Presenter & Author), 2021 American Dairy Science Association (ADSA) Annual Meeting, "Use of wear behavior and material properties for predicting shreddability of process cheese," ADSA, Virtual. (July 11, 2021 - July 14, 2021)


    Progress 06/29/20 to 09/30/20

    Outputs
    Target Audience:The work reported in this period will be of interest to US cheese manufacturing companies particularly those involved in product development and technical services. The main focus of this work is to develop predictive model for shreddability of process cheese using wear behavior and textural properties. The findings from this work will help cheese converters to minimize their operational losses and maximize their profitability. The target groups ie.. cheese manufacturing companies, will be approached through BUILD dairy network. Changes/Problems:We hired a graduate student (Isaac Martineau) to work on objective 2 involving impact of proteolysis and galactose utilization on baking performance of Mozzarella cheese. But he decided to leave his graduate program after finishing one semester. This has put a hold on that objective until we find a replacement for him. What opportunities for training and professional development has the project provided?Jason Young, graduate student has got opportunity to present his work in BUILD dairy annual meeting as well monthly meetings. He also attended professional development courses organized under BUILD dairy program. How have the results been disseminated to communities of interest?Jason Young, graduate student presented his work at the BUILD dairy annual meeting organized during May 27-29, 2020. The meeting was attended by the dairy industry professionals, professors, and students. He presented his update in monthly BUILD Dairy meeting on November 18, 2020. We are planning to submit abstract in ADSA and IFT conferences being organized in year 2021. What do you plan to do during the next reporting period to accomplish the goals?Next step is to develop a shreddability index using the data obtained from shreddability rig and sieve analysis. Further work will involve establishment of correlations between shreddability index and other textural, rheological and wear behavior parameters. Subsequently empirical models will be developed for prediction of shreddability using rheological, wear and textural data. Work on the objective 2 on determination of impact of proteolysis and residual galactose in cheese based on type of cultures used on textural, melting and baking properties of mozzarella cheese will be continued.

    Impacts
    What was accomplished under these goals? The significant work in the objective 1 was accomplished during this year. Total 18 batches of process cheese (PC) with varying spectrum of shreddability were prepared by keeping composition constant but varying extent of intact casein using different age of cheese in the formulation (1-176 days) and emulsifying salt ie. Tri-sodium citrate-TSC (2-3%). A central composite rotatable design (CCRD) was used for 4 (age) x3 (emulsifying salt) factors. Response surface methodology was applied to evaluate effect of variables (formulation type i.e. four formulation with varying level of intact casein as defined by their weighted age (1, 21.7, 82.3, and 101.8 days) or three emulsifier levels (2, 2.5, 3%) on response variables (wear, shreddability, textural parameters). Additional 6 repetitions were carried out on a selected formulation to test power of the model (pure error due to randomness). A correlation analysis was performed for both dependent as well as independent variables. It was evident that with increased proportion of aged cheeses, PC samples exhibited significant effect (P<0.05) on wear behavior, textural attributes and shreaddability parameters. However, effect of emulsifying salt on these parameters was not significant. Frequency sweep test conducted on these samples at 4oC indicated that all the samples were acting like viscoelastic solid material (G'>G"). Degree of frequency dependence of G' at 4oC for these PC formulations was found unaffected with respect to extent of proteolysis or amount of emulsifying salt. The data from all samples supports the idea that the effect of fat at 5? had a significant impact upon its rheological properties overcoming effects arising from treatment variables. Across all the PC formulations the effect of TSC and weighted natural cheese age on wear behavior was determined by measuring by penetration depth and mass removal. For all samples, penetration depth increased as sliding distance increased. Furthermore, the effect of natural cheese on penetration depth and mass removal showed a positive correlation between weighted natural cheese age and the corresponding variables. Wear behavior for PC formulations demonstrated both adhesive and abrasive wear. PC made with 1-day and 21.7-day-old cheese demonstrated abrasive wear as seen on the wear track. These formulations showed very little sticking to the upper PID tribometer geometry during testing. The wear track of these cheeses also illustrated more of a crumbling behavior by the small particles left on either side of the wear track. These formulations exhibited a high degree of adhesion to the upper PID tribometer geometry during testing. The wear track of these cheeses illustrated more of an adhesive wear effect by cheese particles clumping together. For shreddability, the work to grate, crumbliness and adhesion to equipment were measured using two different tests. The treatment effects of average natural cheese age and TSC concentration were measured for each variable. It was determined that the effect of average natural cheese age was significant (P<0.05, n=48) for all test parameters. However, the TSC treatment showed no statistical significance or correlation among treatments. As average natural cheese age increased in PC, the work to grate also increased indicating less ease of grating. Additionally, as average natural cheese age increased in PC adhesion to the equipment increased. These behaviors indicate that there is a positive correlation between cheese adhesion and force to grate, and a negative correlation between crumbliness and force to grate. In texture profile analysis the hardness, adhesiveness, resilience, cohesion, springiness, gumminess and chewiness of PC samples were measured. The effect of average natural cheese age and TSC% were determined. The only statistically significant effect of treatment was the effect of average natural cheese age on hardness and gumminess (P<0.05, n=54). The effect of average natural cheese age on gumminess was similar to that of hardness, and as average natural cheese age increased the gumminess of PC samples decreased. Overall, impact of aged cheese proportion in the PC formulations was found significant on most of the variables. Next step is to establish correlations between these variables and developing empirical models for prediction shreddability using rheological, wear and textural data.

    Publications