Profile of Gelatinolytic Capacity of Raw Goat Milk and the Implications for Milk Quality

作者：W.Y. Chen, Matthew Weng, Shuen‐Ei Chen, Huo-Cheng Peh, W.B. Liu, Ting Yu, Mengyi Huang, M.T. Chen, H. Nagahata, Chung‐Jan Chang · 发表于：Journal of Dairy Science · 年份：2007 · DOI：10.3168/jds.2007-0366 · 被引用次数：11 · 研究领域：Milk Quality and Mastitis in Dairy Cows、Periodontal Regeneration and Treatments、Protease and Inhibitor Mechanisms

Both endogenous and exogenous proteinases occur in milk, and they can have beneficial or detrimental effects on dairy production. Because the lactation length of dairy goats is shorter and the somatic cell count (SCC) of goat milk is generally greater compared with dairy cows, the objectives of the present study were to investigate the prevalence of major proteinases in raw goat milk, their association with SCC and production stage, and their effects on milk quality. Milk samples were collected from individual goats in consecutive weeks for different durations, covering regular lactation, late lactation, and post-milk stasis. Long-term (monthly) or short-term (weekly) fluctuations of milk fibrinolytic and gelatinolytic capacities of individual goats were revealed chronologically on fibrin and gelatin zymograms, respectively. In a separate trial involving milk samples from 23 goats at random production stages, the percentage of ultracentrifuge force-precipitable casein of total milk protein was calculated to represent milk quality and was assessed to evaluate its correlation with the corresponding proteolytic capacities. The results for regular milk indicate that gelatinase B was more abundant than gelatinase A when they first appeared at SCC of approximately 1 x 10(6)/mL. During the last month before milk stasis, both gelatinases A and B were found to be prevalent and prominent in milk regardless of the broad SCC range recorded there. Fibrinolytic activity and the active form...