PDF
Full
Outline
Objective To investigate the key factors that may influence plasmin activity during the production of ultra high temperature (UHT) milk. Methods An enzyme-linked immunosorbent assay (ELISA) was employed to assess and analyze the effects of various factors on plasmin activity throughout the UHT milk production process. The specific factors examined included the degree of mastitis in cows, somatic cell count in milk, vaccination status, changes in feeding conditions, centrifugation processes, pasteurization preheating conditions, microfiltration techniques, and UHT preheating conditions. Results At the raw milk stage, a significant positive correlation was observed between plasmin activity levels in bovine milk and both the severity of bovine mastitis and somatic cell counts. However, no significant correlation was found regarding vaccination status or changes in feed type. During UHT milk production, centrifugal sterilization resulted in a slight increase in plasmin activity; pasteurization preheating at 55 ℃ proved most effective at inhibiting this increase. Microfiltration reduced plasmin activity by approximately 10%. Additionally, varying UHT preheating conditions led to an overall increase in enzyme activity; however, under treatment at 90 ℃ for 5 seconds, a condition yielding only a minimal increase of 1.52%, the rise remained relatively low. Conclusion For pasture, it is essential to focus on managing cows with mastitis and monitoring those milk with abnormal somatic cell counts. At the processing stage, implementing appropriate preheating conditions for pasteurization and UHT can effectively inhibit increases in plasmin activity within milk. Furthermore, incorporating microfiltration can serve as an additional strategy to reduce such enzymatic activities. This study provides a scientific foundation for further research aimed at controlling elevations of plasmin activity in UHT milk.
PDF
284
133
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
