食品科学

• 基础研究 • 上一篇    下一篇

新疆双峰驼乳杀菌条件的选择及其热稳定性

杨 洁,豆智华,李 冠*   

  1. 新疆大学生命科学与技术学院,新疆 乌鲁木齐 830046
  • 出版日期:2013-11-15 发布日期:2013-10-28
  • 通讯作者: 李 冠
  • 基金资助:

    国家自然科学基金项目(31260369)

Selection of Sterilization Conditions for Xinjiang Bactrian Camel Milk and Its Thermal Stability

YANG Jie,DOU Zhi-hua,LI Guan*   

  1. College of Life Science and Technology, Xinjiang University, Ürümqi 830046, China
  • Online:2013-11-15 Published:2013-10-28
  • Contact: LI Guan

摘要:

研究加热温度和时间与驼乳相对密度、滴定酸度、pH值、黏度、酒精稳定性、乳糖含量和总蛋白质含量的关系,用残活率对数值(1g(N/N0))评价杀菌效果,采用SDS-PAGE检测每个热处理水平驼乳蛋白质的变性程度。结果表明:在75℃热处理时间分别为5、10、15min时,菌落总数减少了60.2%、61.9%、81.9%。热处理对驼乳理化指标无显著影响(P>0.05),对酒精稳定性影响显著(P<0.05)。在60~75℃条件下,热处理时间对蛋白质含量的影响不显著(P>0.05);在65~100℃时,热处理温度对乳糖含量的影响显著(P<0.05)。蛋白质的热稳定性:乳酸脱氢酶>α-乳白蛋白>白蛋白>乳铁蛋白。60℃热处理对驼乳中蛋白质的影响不显著(P>0.05)。65~100℃热处理对驼乳中蛋白质的影响显著(P<0.05)。结论:在75℃热处理5~15min,可以杀灭81.9%的微生物,蛋白质的变性程度较低。

关键词: 新疆双峰驼乳, 杀菌条件, 热稳定性, 理化性质

Abstract:

The relative density, titratable acidity, pH, viscosity, alcohol stability, lactose content and total protein content
of mixed milk samples from 10 bactrian camels in Ürümqi suburb, Xinjiang autonomous region were determined as a
function of sterilization temperature and time. The sterilization efficiency was evaluated based on decimal logarithm of
survival fraction (lg (N/N0)). Protein denaturation in milk samples at each thermal treatment was assayed by SDS-PAGE.
The results showed that after 5, 10 min and 15 min at 75 ℃, the total number of colonies was reduced by 60.2%, 61.9% and
81.9%, respectively, without a significant effect on physiochemical parameters (P > 0.05); however, the alcohol stability
was significantly influenced (P < 0.05). Heating time at 60—75 ℃ did not significantly protein content (P > 0.05). Heating
temperatures of 65—100 ℃ exhibited a significant effect on lactose content (P < 0.05). The thermal stability of various
protein components followed the order: lactate dehydrogenase > α-lactalbumin > albumin > lactoferrin. No significant
effect on milk proteins was observed after heat treatment at 60 ℃ (P > 0.05). The effect of heat treatment at 65—100 ℃ on
milk proteins was significant (P < 0.05). From these results, it can be concluded that heat treatment at 75 ℃ for 5—15 min
can kill 81.9% of the microbes in bactrian camel milk, resulting in lower degree of protein denaturation

Key words: bactrian camel milk, sterilization conditions, heat stability, physical and chemical properties

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