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題名 | 生羊乳之乳過氧化酵素系統及其延長貯存期限之研究=Studies on the Lactoperoxidase System and the Use of It to Extend the Storage Period of Goat's Raw Milk |
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作者 | 謝明君; 周繼發; Hsieh, Ming-chun; Chow, Chi-fa; |
期刊 | 中國畜牧學會會誌 |
出版日期 | 19990900 |
卷期 | 28:3 1999.09[民88.09] |
頁次 | 頁401-414 |
分類號 | 463.7 |
語文 | chi |
關鍵詞 | 生羊乳; 乳過氧化酵素系統; 貯存期; Goat's raw milk; Lactoperoxidase system; Storage period; |
中文摘要 | 本研究旨在探討國產生羊乳中乳過氧化酵素系統,簡稱LP系統(lactoperoxidase system; LP system)中之乳過氧化酵素(lactoperoxidase; LP)、硫氰酸鹽(thiocyanate; SCN-) 及過氧化氫(hydrogen peroxide;H2O2)等三成分於全年當中之變化,並探討應用此系統以抑制 生羊乳中之生菌數、低溫菌數及延長其冷藏貯存期之效果。 分析全年12個月生羊乳中乳過氧化酵素、硫氰酸鹽及過氧化氫含量分別為 0.055~0.089mg/mL、0.051~0.065及0.237~0.372mM。冬期乳(9月至翌年2月)之乳過氧化酵 素含量顯著高於暖期乳(3月至8月)(P<0.05),而硫氰酸鹽及過氧化氫含量則差異不顯著。 延長貯存期試驗之結果顯示,單獨調整生羊乳中硫氰酸鹽或過氧化氫含量分別至2.5 mM 時,並不足以產生抑制生菌數之效果。當同時調整生羊乳中之硫氰酸鹽及過氧化氫含量比例 為0.5:0.5、1.5:1.5及2.5:2.5mM時,結果顯示各處理組於4℃冷藏貯存期間,其生菌數皆 遠低於對照組,且未超過處理前之第0日(搾乳後2日)菌數,所有處理之生菌數皆低於100 萬/mL,符合中國國家標準中生乳菌數之要求,亦即各處理應可延長生羊乳貯存期之衛生品質 至6日。就殘留量部份,殺菌處理(HTST)並不影響羊乳中硫氰酸鹽及過氧化氫之殘留量,另 方面,各處理組於殺菌前、後之硫氰酸鹽皆顯著高於對照組,表示殘留量偏高,而各處理之 過氧化氫與對照組差異不顯著。 當調整生羊乳中過氧化氫含量至2.5mM並搭配不同含量硫氰酸鹽時,結果顯示如 SCN-:H2O2為0.5:2.5、1.5:2.5及2.5:2.5mM之各處理組於4℃冷藏貯存期間,生菌及低溫菌 數之抑制效果近似上述之結果。就殘留量而言,0.5:2.5mM處理組於殺菌前、後之硫氰酸鹽 與對照組差異不顯著,但過氧化氫卻顯著高於對照組(P<0.05);而1.5:2.5及2.5:2.5mM處理 之硫氰酸鹽與對照組差異顯著,表示殘留量仍然偏高,但過氧化氫與對照組則差異不顯著。 在此,若考慮低菌數及延長貯存期之條件下,建議分別調整生羊乳中硫氰酸鹽至0.5~1.5mM 及過氧化氫不超過2.5mM。 |
英文摘要 | The purpose of this study was to investigate the alteration of lactoperoxidase, thiocyanate, and hydrogen peroxide for the lactoperoxidase system in goat raw milk within the past 12 months, and also to determine whether it was possible to decrease bacterial counts in goat raw milk and extend the storage life by using the lactoperoxidase system. The original level of lactoperoxidase, thiocyanate and hydrogen peroxide in goat raw milk were 0.055~0.089 mg/mL, 0.051~0.065 mM and 0.237~0.372 mM, respectively. Lacto-peroxidase of goat raw milk in cool seasons (Sep. to Feb.) was higher significantly than in the warm seasons (Mar. to Aug.) (P<0.05). The levels of thiocyanate and hydrogen peroxide between cool and warm seasons were not significantly different. The results of Experiment I showed that the contents of SCN- or H2O2 were adjusted to 2.5 mM did not decrease the standard plate counts of goat's raw milk. Experiment II showed that giving the different SCN- of each treatment to compare standard plate counts (SCN-: H2O2=0.5:0.5,1.5:1.5 and 2.5:2.5 mM) by putting treatments at 4℃, standard plate counts of all treatments were lower than the control on 0 day. All of the standard plate counts of treatments were lower than 106 CFU/mL during 4℃ storage which met the requirements of Chinese National Standard (CNS). In other words, it showed that each treatment could maintain the keeping quality for at least 6 days. Also, HTST did not influence the residual of thiocyanate and hydrogen peroxide. On the other hand, the SCN- of each treatment were much higher than the control both before HTST and after HTST, which meant the residual of treatments were higher than the control. However, H2O2 did not show much difference between the control and the treatments. Experiment III showed that the inhibitory effect on standard plate and psychrotrophic counts was almost the same as the second experiment when giving the different SCN- of each treatment (SCN- H2O2=0.5:2.5, 1.5:2.5 and 2.5:2.5 mM) during 4℃ storing periods. The SCN- residual of 0.5:2.5 mM treatment did not show much difference from the control, but H2O2 residual of this treatment was higher significantly than the control (P<0.05). When comparing the SCN- residual of treatment 1.5:2.5 and 2.5:2.5 mM, they both showed higher significance than the control. However, H2O2 residual of this two treatment did not have obvious higher level than the control. In sum, changing the level of the SCN- to 0.5~1.5 mM and H2O2 to not more than 2.5 mM might decrease standard plate and psychrotrophic counts, and also extend the storage periods of goat raw milk within 6 days after milking. |
本系統之摘要資訊系依該期刊論文摘要之資訊為主。