Progress 01/01/16 to 12/31/20
Outputs
Target Audience:The main target audience for this grant is the US food industry, which will benefit directly from the results of the research. The scientific community, particularly food scientists, will benefit from the generated knowledge regarding the structural changes of food proteins using High Pressure Processing. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students funded through this grant and a third one, funded by the Singaporean government, as well as an undergraduate student have been trained as part of the grant. The graduate students attended a number of conferences, which offered additional opportunities for professional development. A postdoctoral associate from Rutgers University was also funded from the grant, in its last year (for contributions it digestibility work). How have the results been disseminated to communities of interest?The data has been presented at various conferences and industry meetings, included in several publications (with at least 2 more coming after the end date of the grant) and has been discussed broadly with scientists from academia and industry. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Pressure induced structural changes of proteins open up interesting opportunities for the treatment of high concentration protein systems, where HPP treatment may facilitate the creation of unique structures. HPP treatment of milk proteins We investigated the effect of a combination of HPP and enzymatic treatment on structural changes in milk protein concentrates. Milk protein concentrate (MPC) powder was reconstituted to form a 12.5% (w/w) protein solution. Adjustment of pH (5.1 - 6.8) was achieved by adding glucono-delta-lactone (GDL). Chymosin (0 - 450 mg/g casein) was added to the samples, which were then sealed in flexible packaging. Samples were then HPP-treated at 600 MPa for 3 min, at 5°C, in triplicate. After HPP treatment, significant structural changes were observed, which were both rennet and pH dependent. Pressurization of MPC with rennet addition led to extensive protein aggregation and network formation, in a much shorter time compared to conventional methods of gelation. The gel strength of the chymosin-containing sample was twice as high compared to the sample without chymosin. By comparison, pH reduction produced weaker gels. Regardless of whether chymosin is added or not, no significant proteolysis occurred during a 4-week refrigerated storage. These findings demonstrate that controlled, much faster structural modification of high concentration protein systems can be obtained by pressure-assisted enzymatic treatment as compared to conventional enzymatic coagulation. 2. HPP treatment of pea protein concentrates Pea protein concentrate (PPC) and pea starch (PS) powders were dispersed in water to form solutions containing 9%, 12% and 15% (w/w) protein, in combination with up to 8% (w/w) starch. The solutions were sealed in flexible packaging and subjected to HPP at 600 MPa, for 4 min, at 5 °C. Structural changes in the treated samples were investigated by dynamic rheology, differential scanning calorimetry and scanning electron microscopy. HPP induced concentration dependent changes in all mixed systems. While gel formation did not occur for the 9% (w/w) protein-only system, weak gels were formed with the addition of starch. Strong gels were formed for the 12% (w/w) and 15% (w/w) protein concentrations, with gel strength being highly dependent on protein concentration. Compared to controls, HPP treated samples had up to a 1000-fold increase in strength. While HPP induced protein denaturation, starch remained ungelatinized after the pressure treatment. Starch acted as a filler in the pressure induced gels, and did not gelatinize. We have also explored the effects of HPP and heat on the protein and starch digestibility of mixed pea protein-starch systems. The untreated, pressure-treated, and heat-treated samples underwent dynamic in-vitro digestions using the TIM-1 system at Rutgers University. Protein and starch digestibility were investigated using specialized assays. While the untreated samples had the highest protein and the lowest starch digestibility, pressure treatments led to higher protein and lower starch digestibility than heat treatments. These results show that HPP-treated pea protein-starch mixtures could lead to the creation of novel pea-based products with lower glycemic-index and enhanced protein digestibility, without the use of heat or chemical additives. 3. Effect of HPP treatment on plant protein functionality We also evaluated the effects of HPP and heat treatment on the structure and function of pulse (pea, lentil, faba bean) protein concentrates, at protein concentrations characteristic of protein-fortified beverages (5%) and protein gels (15%). Structural differences amongst untreated, HPP-treated (600 MPa, 4 min, in a 50L Hiperbaric unit), and heat-treated (95oC, 15 min) pulse proteins were investigated via differential scanning calorimetry and probing of surface hydrophobicity. Changes in protein functionality were characterized by measuring protein solubility, rheological properties, water holding capacity, emulsifying properties, and foaming properties. Analyses were performed on samples with 5% and/or 15% protein based on food application considerations. Sample preparation, processing, and analyses were performed in triplicate. Data was analyzed statistically using a linear mixed model and significance of treatment was determined using Tukey's multiple comparison test. HPP and heat treatments denatured the pulse proteins and significantly increased surface hydrophobicity, by a factor of 1.8-2.1 for HPP-treated and 1.7-2.8 for heat-treated samples (p<0.05). Significant re-burying of exposed hydrophobic residues was not observed at increasing pressure. HPP- and heat-induced conformational changes led to strong protein gel network formation at 15% protein, with the elastic modulus (G') increasing by 2-4 orders of magnitude upon HPP treatment and 3-5 orders of magnitude upon heat treatment. Water holding capacity significantly increased, from 19-32% for untreated samples to 94-96% for HPP-induced gels and nearly 100% for heat-induced gels (p<0.05). Protein solubility significantly decreased, from 57-65% in the untreated samples to 25-30% for HPP-treated and 22-39% for heat-treated samples (p<0.05). Both treatments increased emulsifying stability, foam expansion, and foam liquid stability, but decreased emulsifying activity. The extent of these changes varied considerably by protein and treatment type. Overall, HPP was able to induce structural and functional changes in pulse proteins comparable to heat treatment. These findings can inform new pulse protein-based product innovations.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Wang L. and Moraru C. I. 2021. Structure and shelf stability of milk protein gels created by pressure-assisted enzymatic gelation. In press. Journal of Dairy Science
- Type:
Journal Articles
Status:
Published
Year Published:
2021
Citation:
Wang L. and Moraru C. I. 2021. High-pressure structuring of milk protein concentrate: Effect of pH and calcium. In press. Journal of Dairy Science
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
Sim S. Y.J. and Moraru C.I. 2020. High pressure processing of pea protein-starch mixed systems: effect of starch on structure formation. JFPE e13352
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
Sim S.Y.J., Karwe M. V. and Moraru C. I. 2019. High pressure induced structuring of pea protein concentrates: the contributions of protein and starch. JFPE. e13261. https://doi.org/10.1111/jfpe.13261
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Wang L. and Moraru C.I. 2019. Pressure-assisted enzymatic gelation of high concentration milk protein systems. Annual Meeting of IFT, New Orleans, LA, June 2019. (poster presentation)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2019
Citation:
Sim S. and Moraru C.I. 2019. Structural Changes Induced by High Pressure Processing in Mixed Pea Protein-Starch Systems. Annual Meeting of IFT, New Orleans, LA, June 2019. (poster presentation)
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Linran Wang and Carmen I. Moraru. 2020. Shelf stability of milk protein gels created by pressure-assisted enzymatic gelation. ADSA Annual Meeting (virtual), June 22-24, 2020.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2020
Citation:
Alexandra E. Hall, Shaun Y.J. Sim, Mukund V. Karwe, and Carmen I. Moraru. 2020. Comparative Effects of High Pressure Processing and Heat Treatment on Pea Protein In Vitro Digestibility. IFT Annual Meeting (virtual), July 13-15, 2020
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2020
Citation:
Linran Wang. 2020. HIGH PRESSURE PROCESSING OF HIGH CONCENTRATION MILK PROTEIN SYSTEMS. PhD Thesis
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2019
Citation:
Shaun Sim. 2019. HIGH PRESSURE PROCESSING OF MIXED PEA PROTEIN-STARCH SYSTEMS: THE EFFECTS ON STRUCTURE AND IN-VITRO DIGESTIBILITY. PhD Thesis
- Type:
Theses/Dissertations
Status:
Awaiting Publication
Year Published:
2021
Citation:
Alexandra Hall. 2021. Comparative Effects of High Pressure Processing and Thermal Treatment on Pulse Protein Structure, Function, and Digestibility. PhD thesis
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Progress 01/01/18 to 12/31/18
Outputs
Target Audience:The main target audience for this project is the US food industry, which will benefit directly from the results of the research. The scientific community, particularly food scientists, will benefit from the generated knowledge regarding the structural changes of food proteins using High Pressure Processing. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students funded through this grant and a third one, funded by the Singaporean government, have been trained as part of the project. The attended a number of conferences, which offered additional opportunities for professional development. How have the results been disseminated to communities of interest?The data has been presented at various conferences and industry meetings, and has been discussed broadly with scientists form academia and industry. What do you plan to do during the next reporting period to accomplish the goals?We are close to completing a study on the effect of HPP on protein-enzyme mixtures. The main focus of the next phase will be to evaluate the digestibility of the HPP treated protein systems.
Impacts
What was accomplished under these goals?
In this stage of the project, we continued to address Objective 1, but focused primarily on addressing Objective 2. The work was conducted on two protein systems: a) pea proteins and b) milk proteins. a) Effect of HPP on pea proteins. Reconstituted pea protein concentrates (PPC) with 8-24 g protein /100 g water were subjected to HPP at 250-550 MPa for 15 min at ambient temperature. For comparison purposes, a set of samples were subjected to heat treatments at 95 °C for 15 min. Structural changes were investigated using dynamic rheology, scanning electron microscopy, differential scanning calorimetry, and mid-infrared spectroscopy. Gel formation occurred at 16 g protein /100 g water concentration and 250 MPa for the HPP-treated samples, and at 12 g protein /100 g water concentration for the heat-treated samples. Gel strength increased with both pressure level and protein concentration; heat-treated samples exhibited greater gel strength than pressure-treated samples at the same protein concentration. A greater extent of protein denaturation, aggregation and network formation occurred with increasing pressure level, due to protein tertiary and quaternary conformation changes. Starch granules present in PPC retained their structure and were not gelatinized even at 550 MPa. b) Effect of HPP on milk proteins. Milk protein concentrate (MPC) powder was reconstituted to form a 12.5% (w/w) protein solution. Adjustment of pH (5.1 - 6.8) was achieved by adding glucono-delta-lactone (GDL). Animal rennet (0 - 450 mg/g casein) was added to the samples, which were then sealed in flexible packaging. Samples were then HPP-treated at 600 MPa for 3 min, at 5°C, in triplicate. After HPP treatment, significant structural changes were recorded, which were both rennet concentration and pH dependent. Pressurization of MPC with rennet addition led to extensive protein aggregation and network formation, in a much shorter time compared to conventional methods of gelation. Without rennet addition or pH adjustment (pH=6.6), the gel strength of HPP-treated MPC, as measured by the storage modulus (G'), had a value of 2240 Pa. G' increased with increasing rennet concentration, reaching as high as 104 Pa. By comparison, pH reduction produced weaker gels, with lower G', ranging from 102 to 103 Pa. These findings demonstrate that controlled, fast structural modification of high concentration protein systems can be obtained by pressure-assisted enzymatic treatment. Overall, this study provides insights into the possibility of using HPP for the development of milk or pea protein based products with novel structures and textures, built-in safety and extended shelf life.
Publications
- Type:
Other
Status:
Other
Year Published:
2018
Citation:
Moraru C.I. 2018. Structure engineering of high protein foods using HPP. Congressional Exhibit, US Senate, Washington DC, June 6, 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Linran Wang, Lee Cadesky, Mukund Karwe and Carmen I. Moraru. 2018. High pressure structure engineering of high concentration milk protein systems. Conference of Food Engineering. Minneapolis, MN, September 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Shaun Sim, Linran Wang, Lee Cadesky, Mukund V. Karwe, and Carmen I. Moraru. 2018. High pressure structure engineering of high concentration food protein systems. IUFoST Congress, Mumbai, India, October 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Linran Wang and Carmen I. Moraru. 2018. High Pressure Structure Engineering of High Concentration Milk Protein Systems: Effect of pH and Calcium. Conference of Food Engineering. Minneapolis, MN, September 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Shaun Sim and Carmen I. Moraru. 2018. High Pressure Induced Structural Changes in Mixed Pea Protein-Starch Systems. Conference of Food Engineering. Minneapolis, MN, September 2018
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Shaun Sim, Linran Wang, Lee Cadesky, Mukund V. Karwe and Carmen I. Moraru. 2018. High Pressure Structure Engineering of High Concentration Food Protein Systems. IUFoST Congress, Mumbai, India, October 2018
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Progress 01/01/17 to 12/31/17
Outputs
Target Audience:The main target audience for this project is the US food industry, which could benefit directly from the results of this research. The scientific community, particularly food scientists, will benefit from the generated knowledge regarding the structural manipulations of food proteins using High Pressure Processing. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?Two graduate students - one funded through the project and one funded by the Singaporean government - have been trained as part of the project. How have the results been disseminated to communities of interest?The results of our research to date have been communicated to the scientific community through conference presentations. What do you plan to do during the next reporting period to accomplish the goals?We will continue our investigations on the effect of HPP on food proteins, and initiate the work on the effect of HPP on the digestibility of the HPP treated protein samples.
Impacts
What was accomplished under these goals?
Pressure induced structural changes of proteins open up interesting opportunities for the treatment of high concentration protein systems, where HPP treatment may facilitate the creation of unique structures. During the past year we investigated the effect of HPP treatment on milk proteins and pulse proteins, and highlight new product opportunities resulting from the HPP treatment of milk protein concentrate (MPC), micellar casein concentrate (MCC) and pea protein concentrate (PPC). High pressure treatment of MPC and MCC of up to 10% (w/w) protein concentration and PPC of up to 24% (w/w) protein concentration were subjected to 15 min HPP treatments at pressures from 150 MPa to 550 MPa, at ambient temperatures. HPP treatments induced significant changes, which were both concentration and pressure dependent, in all protein concentrates. Most significantly, gel formation occurred after pressure treatments above 250 MPa and 10% protein (w/w) concentration, due to protein gelation. For PPC, starch gelatinization also had a minor contribution to structure formation. The results of this research further the understanding of pressure-induced changes in concentrated protein systems, and provide a basis for the development of gelled protein based products, without the use of heat or chemical additives.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
3. Cadesky L., Ribeiro M.W., Kriner K., Karwe M.V., and Moraru C.I. 2017. Structural changes induced by high pressure processing in micellar casein and milk protein concentrates. Journal of Dairy Science 100(9):7055-7070
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2017
Citation:
Moraru C.I., Sim S., Cadesky L. and Karwe M. 2017. High Pressure as a New Method for Creating Food Protein Gels. Nonthermal Processing Workshop. IIT-IFSH. Chicago, IL, May 23-26, 2017
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Progress 01/01/16 to 12/31/16
Outputs
Target Audience:The main target audience for this project is the US food industry, which could benefit directly from the results of this research. The scientific community, particularly food scientists, will benefit from the generated knowledge regarding the structural manipulations of food proteins using High Pressure Processing. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?As part of this grant, we have been training 2 graduate students from Cornell University, 1 graduate student from Rutgers University and one postdoctoral associate from Rutgers University. How have the results been disseminated to communities of interest?We have already reported our findings at national and international conferences, and already submitted a manuscript for publication. What do you plan to do during the next reporting period to accomplish the goals?In the next year we will continue our studies on the effect of HPP on food proteins, and plan to: 1) look deeper into the mechanisms causing the observed structural changes: 2) apply our findings to date to start generating food matrices using HPP (i.e. cheese like products); 3) set up the experiments to determine the digestibility of the HPP treated proteins.
Impacts
What was accomplished under these goals?
In the first year of the project, we focused primarily on addressing Objective 1. Specific ally, we evaluated the effect opf HPP on the structure and properties of milk protein concentrates and pea (as a representative for pulses) protein concentrates. 1. Effect of HPP on milk protein concentrates. Reconstituted micellar casein concentrates (MCC) and milk protein concentrates (MPC) of 2.5% and 10% (w/v) casein were subjected to high pressure treatments at pressures from 150 MPa to 450 MPa, for 15 min at sub-ambient temperatures. Structural changes induced in milk proteins by HPP were investigated using both physical methods (dynamic light scattering, rheology, scanning electron microscopy) and chemical methods (renneting behavior, soluble mineral and protein composition). The experimental data clearly indicated pressure induced changes of casein micelles, as well as denaturation of serum proteins. Levels of calcium binding αs1- and αs2-casein in the soluble phase increased after all pressure treatments. Pressurization up to 350 MPa increased levels of soluble calcium and phosphorous, in all samples and concentrations, while treatment at 450 MPa resulted in a decrease in soluble Ca and P to levels close to those of untreated samples. Structural changes were also supported by the observed changes in renneting behavior. In 10% MCC and 10% MPC, pressurization up to 450 MPa significantly increased the strength of rennet gels and decreased renneting time. Treatment at 450 MPa of 10% MCC and 10% MPC samples resulted in weak gel structures, composed of uniformly distributed, spherical casein substructures of 15-20 nm in diameter. These results may help in the development on new milk protein based foods with novel textures and potentially high sensory and nutritional quality. In particular, the soft gel structures formed at high pressure levels can be the basis for novel milk protein based products. 2. Effect of HPP on pulse protein concentrates We used HPP to induce controlled structural modifications in pea protein concentrates (PPC), with the goal of developing novel textures. PPC powders were dispersed in water to 8.0, 12.0, 16.0, 20.0 and 24.0% protein (w/w) concentration solutions. The protein solutions were then subjected to 15 min HPP treatments at 250, 350, 450 and 550 MPa at 10-25 °C, in a 10 L high pressure unit. Dynamic rheological measurements of the pressure treated samples and untreated controls were conducted. HPP induced significant changes in PPC, which were both concentration and pressure dependent. Gel formation occurred above 450 MPa, with gel strength increasing with concentration. Compared to the untreated controls, HPP treated samples had 10 to 1000-fold increase in storage modulus (G') and loss modulus (G''). The high pressure conditions used also induced starch gelatinization. These findings suggest that HPP treatment of pea protein concentrates at ambient temperatures can result in unique structures and textures, without the utilization of heat or additional ingredients.
Publications
- Type:
Conference Papers and Presentations
Status:
Accepted
Year Published:
2016
Citation:
S. Sim, M.V. Karwe, and C.I. Moraru. 2016. Structural Changes of Pea Protein Concentrates Induced by High Pressure Processing. Conference of Food Engineering, Columbus, OH, September 2016.
- Type:
Journal Articles
Status:
Submitted
Year Published:
2016
Citation:
Cadesky L., Ribeiro M.W., Karwe M.V., and Moraru C.I. 2016. Structural changes induced by high pressure processing in micellar casein and milk protein concentrates. Journal of Dairy Science
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