牦牛肉在发酵过程中pH值及微生物的变化  

The change of pH value and microorganism in the fermentation process of Yak meat

作　　者：周玉春[1] 张丽[1,2] 孙宝忠[2] 姬秋梅[3] 余群力[1] 达娃央拉[3] 李海鹏[2] 谢鹏[2] 郭兆斌[1] 王莉[1] 

机构地区：[1]甘肃农业大学食品科学与工程学院,甘肃兰州730070 [2]中国农业科学院北京畜牧兽医研究所,北京100193 [3]西藏自治区农牧科学院畜牧兽医研究所,西藏拉萨850009

出　　处：《食品与发酵工业》2014年第8期246-251,共6页Food and Fermentation Industries

基　　金：甘肃省农业生物技术研究与应用开发项目(GNSW-2012-18);青藏高原特色有机畜产品生产技术与产业模式(201203009);国家肉牛牦牛产业技术体系(nycytx-38)

摘　　要：为了研究牦牛肉发酵过程中pH值及微生物的变化,以斯布和甘南牦牛半腱肌为原料,嗜酸乳杆菌作为发酵剂,进行发酵肉的制作。在发酵过程中分别对发酵肉的pH值、菌落总数、大肠菌群和乳酸菌总数进行了测定。研究发现,牦牛肉在发酵过程中,斯布和甘南发酵肉在发酵第5天pH值降到最低值,分别为4.63和4.77,此后pH值变化差异均不显著(P>0.05);菌落总数先缓慢上升,后趋于稳定,在7.00 lg(CFU/g)上下波动;斯布和甘南牦牛发酵肉的大肠菌群数均在发酵第5天达到最大值,分别为6.22和6.45 lg(CFU/g),从发酵第5天开始均呈下降趋势,其中甘南牦牛发酵肉大肠菌群下降差异显著(P<0.05);斯布发酵肉在发酵前3天乳酸菌总数显著增加(P<0.05),从第5天开始,乳酸菌总数变化差异不显著(P>0.05),而甘南发酵肉在整个发酵过程中乳酸菌总数变化差异均不显著(P>0.05);斯布和甘南发酵肉的pH值和菌落总数均呈现负相关(r=-0.643),斯布发酵肉的pH值负相关于乳酸菌总数(r=-0.643),而乳酸菌总数正相关于菌落总数(r=0.857)。Acidity, aerobic plate count （APC）, coliforms and lactic acid bacteria（LAB） were important indexes that were used to evaluate the fermentation characteristics and the contamination of microorganism in the process of fermented meat. This study used semitendinosus of Sibu and Gananan as material meat and Lactobacillus acidophilus as starter culture to produce the fermented meat. The pH value, APC, coliforms and LAB were determined in the fer- mented process. Results showed that the pH value of Sibu and Gannan fermented meat had the lowest value （4.63 and 4.77） on Day 5. And the changes of the pH value was not significant （P 〉 0.05） after Day 5. APC rose slowly and then basically kept stable at 7.00 lgCFU/g. Coliforms of Sibu and Gannan fermented meat were at the highest value （6.22 and 6. 451gCFU/g） on Day 5. From Day 5, the tendency declined and the decline of cliforms of Gannan fermented meat was significant （P 〈 0.05 ）. LAB of Sibu fermented meat increased significantly in first three days of fermentation. From Day 5, the change of LAB was not significant （P 〉0. 05） , while Gannan fermented meat was not significant （P 〉 0.05） in the whole fermentation process. The pH value and APC showed a negative correlation in both Sibu and Gannan fermented meat （r = -0. 643 ）, the pH value was negative correlation with LAB （r = - 0. 643） while LAB was positive correlation with APC in Sibu fermented meat （r = 0. 857）.

关 键 词：牦牛肉 发酵 PH值 微生物变化 

分 类 号：TS251.52[轻工技术与工程—农产品加工及贮藏工程]