• EI
    • CSA
    • CABI
    • 卓越期刊
    • CA
    • Scopus
    • CSCD
    • 核心期刊

影响原料乳品质的纤溶酶活性的因素分析

张书文, 刘鹭, 孙洁, 李红娟, 崔文明, 芦晶, 吕加平

张书文, 刘鹭, 孙洁, 李红娟, 崔文明, 芦晶, 吕加平. 影响原料乳品质的纤溶酶活性的因素分析[J]. 农业工程学报, 2014, 30(13): 286-292. DOI: 10.3969/j.issn.1002-6819.2014.13.035
引用本文: 张书文, 刘鹭, 孙洁, 李红娟, 崔文明, 芦晶, 吕加平. 影响原料乳品质的纤溶酶活性的因素分析[J]. 农业工程学报, 2014, 30(13): 286-292. DOI: 10.3969/j.issn.1002-6819.2014.13.035
Zhang Shuwen, Liu Lu, Sun Jie, Li Hongjuan, Cui Wenming, Lu Jing, Lü Jiaping. Analysis on factors affecting plasmin activity of raw milk quality[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2014, 30(13): 286-292. DOI: 10.3969/j.issn.1002-6819.2014.13.035
Citation: Zhang Shuwen, Liu Lu, Sun Jie, Li Hongjuan, Cui Wenming, Lu Jing, Lü Jiaping. Analysis on factors affecting plasmin activity of raw milk quality[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2014, 30(13): 286-292. DOI: 10.3969/j.issn.1002-6819.2014.13.035

影响原料乳品质的纤溶酶活性的因素分析

基金项目: 国家自然科学基金项目(31301521,31371808);现代农业产业技术体系北京市奶牛产业创新团队;国家科技支撑计划(2012BAD29B03,2013BAD18B10);

Analysis on factors affecting plasmin activity of raw milk quality

  • 摘要: 为了充分了解原料乳中纤溶酶活性,以便从源头上提高原料乳品质,该文针对中国原料乳的生产现状,分析了奶牛品种、胎次、养殖模式及挤奶时间对原料乳中纤溶酶活性的影响,并对纤溶酶的热稳定性进行了研究。结果表明,养殖模式、奶牛品种及胎次对原料乳中纤溶酶活性影响显著(P<0.05),牧场养殖、1、4胎和娟珊牛原料乳中纤溶酶活性显著低于养殖小区、2、3胎及荷斯坦牛乳中的纤溶酶活性;挤奶时间对原料乳中纤溶酶活性影响不显著(P>0.05);原料乳中纤溶酶活性随热处理温度的升高而逐渐下降,巴氏杀菌(75℃、15 s)仅可使原料乳中纤溶酶活性下降25%;半胱氨酸对乳中纤溶酶活性具有一定的抑制作用。研究结果对根据纤溶酶活性对原料乳进行品质评价及分级具有一定借鉴作用。
    Abstract: Abstract: Plasmin(PL) is by far the predominant and most completely studied endogenous protease in bovine milk. PL activity level is an important factor affecting dairy product quality and its processing characteristics. Raw milk with a high PL level can have detrimental effects on the quality of pasteurized milk and UHT milk, causing undesirable flavor, precipitation and gelation, and shortening the shelf life of the product. Considerable research has focused on minimizing the activity of PL in fluid milk. Many factors, such as pH, mineral content, whey proteins, and storage temperature can influence the kinetics of the PL-induced hydrolysis. However, according to China's current raw milk production situatioin, the objective of this study is to determine how such factors such as cattle breed, parity, dairy farming mode, and milking time affect PL activity in milk; thermal stability of plasmin is also studied. The results show that the PL activity between dairy farming mode, parity, and cow breeds are significant (P<0.05). Although there are effects of dairy farming mode, parity, and cow breeds on plasmin activity, they are lower in large scale farming, parity (1,4), and Jersey cows. However, the effect of the milking time on PL activity is not significant (P>0.05). PL activity of raw milk gradually decreases with increasing thermal treatment temperature. However, the thermal treatment associated with pasteurization of milk (75℃, 15 sec) has been shown to increase PL levels. This increase in PL activity has long been attributed to inactivation of plasmin inhibitors(PI) and plasminogen activator inhibitors(PAI), but plasminogen activators (PA)is even more heat stable than PIand PAIduring pasteurization and UHT. In this temperature range, plasminogen (PG) loses its naturally occurring tertiary structure, but is not yet inhibited. On the contrary, PG becomes more accessible to the action of PA by unfolding of its kringles. Activation of PG is enhanced upon pasteurization heating. Further heat treatment has been shown to reduce PL levels. PL activity only decreases 25 percent after pasteurized (75℃, 15 sec) treatment. The effects of cysteine addition and heat treatment on PL activity is also studied. The results show that cysteine has some inhibited effect on PL activity in milk. When milk was stored after heat treatment (75℃), there is a decrease in PL activity. PL activity is significantly affected due to interactions with cysteine, which contains free SH groups that cause irreversible denaturation of PL by S-S/S-H interaction. When milk is heated to higher temperatures of 85℃ or 90℃, a larger decrease in PG activity and no further increase in PL activity is observed. This is due to PG interaction with cysteine. PG activity is tested in the presence of cysteine, which causes a marked decrease in PG activity. Two-dimensional electrophoresis confirms that heating of PG in the presence of cysteine causes polymerization of PG into dimers, trimers, and polymers through disulfide interchange. Formation of polymers hinders the activation of PG into PL. This result suggests that the addition of cysteine prior to the pasteurization significantly decreases the potential for proteolysis caused by the PL system during storage. This study has certain reference value to the quality evaluation and grading of raw milk.
  • [1] Bastian E D, Brown R J. Plasmin in milk and dairy products: An update[J]. International Dairy Journal, 1996, 6(5): 435-457.
    [2] Ismail B, Nielsen S S. Invited review: Plasmin protease in milk: Current knowledge and relevance to dairy industry[J]. Journal of Dairy Science, 2010, 93(11): 4999-5009.
    [3] Nielsen S S. Plasmin system and microbial proteases in milk: characteristics, roles and relationship[J]. Journal of Agricultural and Food Chemistry, 2002, 50(22): 6628-6634.
    [4] McSweeney P L H, Fox F. Advanced Dairy Chemistry [M]. Springer, 2012: 337-386.
    [5] Kennedy A, Kelly A L. The influence of somatic cell count on the heat stability of bovine milk plasmin activity[J]. International Dairy Journal, 1997, 7(11): 717-721.
    [6] Richardson B C. The proteinases of bovine milk and the effect of pasteurization on their activity[J]. Zealand Journal of Dairy Science Technology 1983, 18(3): 223-245.
    [7] Grufferty M B, Fox P F. Milk alkaline proteinase[J]. Journal Dairy Research, 1988, 55(4): 609-630.
    [8] Politis, Barbano D M, Gorewit RC. Distribution of plasminogen and plasmin in fractions of bovine milk[J]. Journal of Dairy Science, 1992, 75(6): 1402-1410.
    [9] Caessens P W J R, Daamen W F, Gruppen H, et al. Beta-lactoglobulin hydrolysis: Peptideidentification, SH/SS exchange, and functional properties of hydrolysate fractions formed by the action of plasmin[J]. Journal Agriculture Food Chemistry, 1999, 47(4): 2980-2990.
    [10] 吕加平,王辉,刘鹭. 原料乳耐热蛋白酶对UHT乳品质的影响[J]. 农产品食品科技,2010,4(2):3-9.Lü Jiaping, Wang Hui, Liu Lu. Effects of heat-resistant protease from yaw milk on quality of UHT milk[J]. Agricultural food products science and technology, 2010, 4(2): 3-9. (in Chinese with English abstract)
    [11] 王辉,吕加平,刘鹭,等. 耐热蛋白酶对UHT乳蛋白的水解作用[J]. 食品科学,2010,31(17):228-231.Wang Hui, Lü Jiaping, Liu Lu, et al. Hydrolysis effect of heat-resistant protease on UHT milk[J]. Food Science, 2010, 31(17): 228-231. (in Chinese with English abstract)
    [12] Datta N, Deeth H C. Age gelation of UHT milk-a review[J]. Food and Bioproducts Processing, 2001, 79(4): 197-210.
    [13] 张和平. 原料乳体细胞与原料乳质量及加工特性的关系[M]. 北京:中国轻工业出版社,2012:75-90.Zhang H P. The Relationship Among Somatic Cell, Milk Quality and Processing Properties of Raw Milk[M]. Beijing: China Light Industry Press, 2012: 75-90.
    [14] Bastian E D, Brown R J, Ernstorm C A. Plasmin activity and milk coagulation[J]. Journal Dairy Science, 1991, 74(11): 3677-3685.
    [15] Devon Durkee, Kirby Hayes. Effects of cysteine addition and heat treatment during non-fat dry milk processing on the plasmin enzyme system[J]. Dairy Science and Technology, 2008, 88 (1): 81-94.
    [16] 陆东锋,刘太宇. 奶牛场与奶牛小区原料牛奶质量指标的研究[J]. 郑州牧业工程高等专科学校学报,2009,29(1):15-18.Lu Dongfeng, Liu Taiyu. Study on quality guidelines of raw[J]. Journal of Zhengzhou College of Animal Husbandry Engineering, 2009, 29(1): 15-18. (in Chinese with English abstract)
    [17] 吕加平,张书义,王辉,等. 原料乳体细胞数与纤溶酶活性的相关性研究[J]. 中国乳品工业,2010, 38(3):4-6.Lü Jiaping, Zhang Shuyi, Wang Hui, et al. Relativity of SCC and plasmin activity in raw milk[J]. China Dairy Industry, 2010, 38(3): 4-6. (in Chinese with English abstract)
    [18] Ballou L U, Pasquini M, Bremel R D, et al. Factors affecting herd milk composition and milk plasmin at four levels of somatic cell counts[J]. Journal of Dairy Science, 1995, 78(10): 2186-2195.
    [19] Klei L R, Lynch J M, Barbano D M, et al. Influence of milking three times a day on milk quality[J]. Journal Dairy Science, 1997, 80(3): 427-36.
    [20] 梁霄,刘鹭,张书文,等. 不同品种原料乳理化特性分析[J]. 食品科学,2013,34(5):50-54.Liang Xiao, Liu Lu, Zhang Shuwen, et al. Analysis of physicochemical properties of different raw milk[J]. Food Science, 2013, 34(5): 50-54. (in Chinese with English abstract)
    [21] Korycha-Dahl M, Dumas B R, Chene N, et al. Plasmin activity in milk[J]. Journal ofDairy Science, 1983, 66(4): 704-711.
    [22] Richardson B C. Variation of concentration of plasmin and plasminogen in bovine milk with lactation[J]. New Zealand Journal of Dairy Science and Technology, 1983, 18(3): 247-252.
    [23] Theodorou G. Factors affecting the plasmin-plasminogen system in milk obtained from three Greek dairy sheep breeds with major differences in milk production capacity[J]. Journal of Dairy Science, 2007, 90(7): 3263-3269.
    [24] Johan Schaar. Plasmin activity and proteose-peptone content of individual milks[J]. Journal of Dairy Research, 1985, 52(3): 369-378.
    [25] Prado B M, Sombers S E, Ismail B, et al. Effect of heat treatment on the activity of inhibitors of plasmin and plasminogen activators in milk[J]. International Dairy Journal, 2006, 16(6): 593-599.
    [26] Lu R R, Stevenson C D, Guck S E, et al. Effect of various heat treatments on plasminogen activation in bovine milk during refrigerated storage[J]. International Journal of Food Science and Technology, 2009, 44(4): 681-687.
    [27] Thierry S D, Gérard H, Jean L G. Heat inactivation of native plasmin, plasminogen and plasminogen activators in bovine milk: A revisited study[J]. Lait, 2001, 81(6): 715-729.
    [28] Metwalli A A M, Jongh H H J, Boekel M A J S. Heat inactivation of bovine plasmin[J]. International Dairy Journal, 1998, 8(1): 47-56.
    [29] Ryan K N, Stevenson C D, Hayes K D. Mechanism of decreased heat-induced activation of plasminogen in the presence of cysteine[J]. International Dairy Journal, 2012, 23(2): 79-85.
计量
  • 文章访问数:  2425
  • HTML全文浏览量:  0
  • PDF下载量:  1191
  • 被引次数: 0
出版历程
  • 收稿日期:  2013-11-17
  • 修回日期:  2014-04-26
  • 发布日期:  2014-06-30

目录

    /

    返回文章
    返回