食品科学 ›› 2009, Vol. 30 ›› Issue (19): 162-165.doi: 10.7506/spkx1002-6630-200919036

• 生物工程 • 上一篇    下一篇

不同体细胞数牛乳中纤溶酶热变性动力学研究

王辉1,吕加平2,迟玉杰3,靳磊2   

  1. 1. 中国农科院农产品加工研究所,农业部农产品加工与质量控制重点开发实验室
    2. 国家知识产权局专利审查协作中心 3. 东北农业大学食品学院
  • 收稿日期:2008-10-30 修回日期:2009-07-29 出版日期:2009-10-01 发布日期:2010-12-29
  • 通讯作者: 吕加平 E-mail:lvjp586@vip.sina.com
  • 基金资助:

    “十一五”国家科技支撑计划项目2006BAD04A07 2006BAD04A10)
    国家科研院所社会公益项目(2002005DIA4G035-7)

Kinetics Studies on Thermo-inactivation of Plasmin in Milk with Various Amounts of Somatic Cells

WANG Hui1,2 LU Jia-ping1,* CHI Yu-jie3 JIN Lei1   

  1. 1. Institute of Agro-food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agricultural Product
    Processing and Quality Control, Ministry of Agriculture, Beijing 100193, China 2.Patent Examination Cooperation Center of
    SIPO, Beijing 100190, China 3.College of Food Science, Northeast Agricultural University, Harbin 150030, China
  • Received:2008-10-30 Revised:2009-07-29 Online:2009-10-01 Published:2010-12-29
  • Contact: LU Jia-ping1,* E-mail:lvjp586@vip.sina.com

摘要:

通过对高体细胞数(HSCC 100万个/mL)和低体细胞数(LSCC 30万个/mL)原料乳中纤溶酶进行65-130℃范围内热处理,探究牛乳体系中纤溶酶热变性动力学规律。结果表明:纤溶酶在热变性过程中显示了典型的一级方程(n=1);经不同热处 理后,牛乳中纤溶酶活性均下降;65-85℃范围的巴氏杀菌对纤溶酶活性影响不显著(P>0.05),超高温灭菌处理对纤溶酶活性影响显著(P<0.05);HSCC样品在≤110℃范围内的D值都大于LSCC样品,在T=130℃时,HSCC样品的D值为53.75S,LSCC样品D值为58.94S;HSCC和LSCC乳中纤溶酶热失活表观活化能Ea在65-95℃范围内分别为65.76kJ/mol和57.26kJ/mol,在95-130℃范围内分别为22.12kJ/mol和21.48kJ/mol。结论:巴氏杀菌范围内,热处理对牛乳中纤溶酶活性影响不显著,HSCC乳中纤溶酶活性比LSCC乳中的更稳定些;超高温灭菌处理后,两样品中纤溶酶活性明显下降,稳定性无差异。

关键词: HSCC牛乳, LSCC牛乳, 纤溶酶, 热变性, 动力学, 表观活化能

Abstract:

The thermo-inactivation kinetic law of plasmin in milk was studied by heating high somatic cell count (HSCC) and low somatic cell count (LSCC) milk at 65 130 , respectively. Results revealed that plasmin inactivation kinetics in milk was in agreement with classic first-order equation. Plasmin activity decreased through heating at different temperatures. No significant difference of plasmin activity was observed after pasteurization at 65 85 (P 0.05), but plasmin activity of either HSCC or LSCC milk exhibited a significant difference through thermal treatments at ultra-high temperatures (P 0.05). The D value (the time for 90% plasmin inactivation) of HSCC milk was larger than that of LSCC milk below 110 ; however, the D-value was determined to be 53.75 s for HSCC milk and 58.94 s for LSCC milk at 130 , respectively. The apparent activation energy (Ea) for HSCC and LSCC milk was 65.76 and 57.26 kJ/mol at 65 95 , 22.12 and 21.48 kJ/mol at 95 130 , respectively. Therefore, no significant difference for plasmin activity is observed in high and low SCC milk with low temperature treatments (65 85 ) through pasteurization. Moreover, HSCC milk shows a higher stability than LSCC milk. In contrast, both HSCC and LSCC milk exhibit an obvious decrease in plasmin activity and no difference in thermostability through ultra-high temperature treatments.

Key words: HSCC milk , LSCC milk , plasmin, thermo-inactivation , kinetic , apparent activation energy

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