Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk
This study investigated the effects of isochoric freezing (IF) on the shelf-life and quality of raw bovine milk over a 5-week period. The results were compared with conventional refrigeration (RF) and refrigeration after pasteurization (HTST). The IF treatment process entailed storing liquid raw mil...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2023-11-01
|
| Series: | Foods |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2304-8158/12/22/4150 |
| _version_ | 1827639856867573760 |
|---|---|
| author | Alan L. Maida Cristina Bilbao-Sainz Andrew Karman Gary Takeoka Matthew J. Powell-Palm Boris Rubinsky |
| author_facet | Alan L. Maida Cristina Bilbao-Sainz Andrew Karman Gary Takeoka Matthew J. Powell-Palm Boris Rubinsky |
| author_sort | Alan L. Maida |
| collection | DOAJ |
| description | This study investigated the effects of isochoric freezing (IF) on the shelf-life and quality of raw bovine milk over a 5-week period. The results were compared with conventional refrigeration (RF) and refrigeration after pasteurization (HTST). The IF treatment process entailed storing liquid raw milk in isochoric chambers in thermodynamic equilibrium at −5 °C/77 MPa and −10 °C/96 MPa. Several parameters were analyzed, including microbiology count, physicochemical properties, indigenous enzyme activity, protein content, volatile organic compounds profile, and lipid degradation. Both raw and pasteurized milk experienced increases in the microbial level past the acceptable threshold (≥5.5 log CFU/mL) after 2 weeks and 5 weeks, respectively, leading to the deterioration of other parameters during storage. In comparison, microbiology count decreased significantly during storage for both IF treatment conditions but was more pronounced for the higher pressure (96 MPa) treatment, leading to undetectable levels of microorganism after 5 weeks. IF treatment maintained stable pH, titratable acidity, viscosity, lipid oxidation, volatile profiles, total protein content, and lactoperoxidase activity throughout the storage period. Color was preserved during IF treatment at −5 °C/77 MPa; however, color was impacted during IF treatment at −10 °C/96 MPa. Protein structures were also modified during pressurized storage in both IF treatments. Overall, the study demonstrated that isochoric freezing could significantly increase the shelf-life of milk by reducing microbiology activity, whilst maintaining its nutritional content. These results underscore the potential role of isochoric freezing as a valuable tool in eliminating pathogens while maintaining quality characteristics similar to raw milk over long storage periods. |
| first_indexed | 2024-03-09T16:49:55Z |
| format | Article |
| id | doaj.art-733babca042c429a85f521aa1f49b1ea |
| institution | Directory Open Access Journal |
| issn | 2304-8158 |
| language | English |
| last_indexed | 2024-03-09T16:49:55Z |
| publishDate | 2023-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Foods |
| spelling | doaj.art-733babca042c429a85f521aa1f49b1ea2023-11-24T14:42:14ZengMDPI AGFoods2304-81582023-11-011222415010.3390/foods12224150Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine MilkAlan L. Maida0Cristina Bilbao-Sainz1Andrew Karman2Gary Takeoka3Matthew J. Powell-Palm4Boris Rubinsky5Department of Mechanical Engineering, University of California, 6141 Etcheverry Hall, Berkeley, CA 94720, USAU.S. Department of Agriculture, Western Regional Research Center, 800 Buchanan St., Albany, CA 94710, USAU.S. Department of Agriculture, Western Regional Research Center, 800 Buchanan St., Albany, CA 94710, USAU.S. Department of Agriculture, Western Regional Research Center, 800 Buchanan St., Albany, CA 94710, USAJ. Mike Walker ’66 Department of Mechanical Engineering, Texas A&M University, 3123 TAMU, College Station, TX 77843, USADepartment of Mechanical Engineering, University of California, 6141 Etcheverry Hall, Berkeley, CA 94720, USAThis study investigated the effects of isochoric freezing (IF) on the shelf-life and quality of raw bovine milk over a 5-week period. The results were compared with conventional refrigeration (RF) and refrigeration after pasteurization (HTST). The IF treatment process entailed storing liquid raw milk in isochoric chambers in thermodynamic equilibrium at −5 °C/77 MPa and −10 °C/96 MPa. Several parameters were analyzed, including microbiology count, physicochemical properties, indigenous enzyme activity, protein content, volatile organic compounds profile, and lipid degradation. Both raw and pasteurized milk experienced increases in the microbial level past the acceptable threshold (≥5.5 log CFU/mL) after 2 weeks and 5 weeks, respectively, leading to the deterioration of other parameters during storage. In comparison, microbiology count decreased significantly during storage for both IF treatment conditions but was more pronounced for the higher pressure (96 MPa) treatment, leading to undetectable levels of microorganism after 5 weeks. IF treatment maintained stable pH, titratable acidity, viscosity, lipid oxidation, volatile profiles, total protein content, and lactoperoxidase activity throughout the storage period. Color was preserved during IF treatment at −5 °C/77 MPa; however, color was impacted during IF treatment at −10 °C/96 MPa. Protein structures were also modified during pressurized storage in both IF treatments. Overall, the study demonstrated that isochoric freezing could significantly increase the shelf-life of milk by reducing microbiology activity, whilst maintaining its nutritional content. These results underscore the potential role of isochoric freezing as a valuable tool in eliminating pathogens while maintaining quality characteristics similar to raw milk over long storage periods.https://www.mdpi.com/2304-8158/12/22/4150isochoric freezingbovine milkmicrobial inactivationshelf-lifevolatile compoundsthermal pasteurization |
| spellingShingle | Alan L. Maida Cristina Bilbao-Sainz Andrew Karman Gary Takeoka Matthew J. Powell-Palm Boris Rubinsky Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk Foods isochoric freezing bovine milk microbial inactivation shelf-life volatile compounds thermal pasteurization |
| title | Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk |
| title_full | Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk |
| title_fullStr | Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk |
| title_full_unstemmed | Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk |
| title_short | Effects of Isochoric Freezing on the Quality Characteristics of Raw Bovine Milk |
| title_sort | effects of isochoric freezing on the quality characteristics of raw bovine milk |
| topic | isochoric freezing bovine milk microbial inactivation shelf-life volatile compounds thermal pasteurization |
| url | https://www.mdpi.com/2304-8158/12/22/4150 |
| work_keys_str_mv | AT alanlmaida effectsofisochoricfreezingonthequalitycharacteristicsofrawbovinemilk AT cristinabilbaosainz effectsofisochoricfreezingonthequalitycharacteristicsofrawbovinemilk AT andrewkarman effectsofisochoricfreezingonthequalitycharacteristicsofrawbovinemilk AT garytakeoka effectsofisochoricfreezingonthequalitycharacteristicsofrawbovinemilk AT matthewjpowellpalm effectsofisochoricfreezingonthequalitycharacteristicsofrawbovinemilk AT borisrubinsky effectsofisochoricfreezingonthequalitycharacteristicsofrawbovinemilk |