摘要
将益生菌Lb.casei Zhang分别以0、2×106、4×106、1×107cfu/g的添加量,与商业酸乳发酵剂YC-X11共同接种进行酸乳制备。分别在发酵及贮藏期间测定酸乳样品的pH值、粘度及S.thermophilus,L.delbrueckii subsp.bulgaricus和Lb.casei Zhang的活菌数,并对上述指标之间的相关性进行了分析。结果表明,在发酵6h后,添加Lb.casei Zhang的酸乳样品,其pH值变化及S.thermophilus和L.delbrueckii subsp.bulgaricus的活菌数均与对照组差异不明显(p<0.05),且各组酸乳样品测定指标间无相关性(p<0.05)。变温贮藏21d期间,添加Lb.casei Zhang的酸乳样品,其pH值、粘度、脱水收缩敏感性及S.thermophilus的活菌数与对照组差异不显著(p<0.05);添加Lb.casei Zhang的酸乳样品中L.delbrueckii subsp.bulgaricus的活菌数明显低于对照组(p<0.05)。Lb.casei Zhang的添加量为2×106和1×107cfu/g时,样品pH值均与粘度呈显著正相关(p<0.05),添加量4×106cfu/g的Lb.casei Zhang时,样品粘度与脱水收缩敏感性及pH值与活菌数均呈显著负相关(p<0.05)。
Probiotic Lb. casei Zhang was inoculated at different level of 0, 2×10^6, 4×10^6, 1×10^7 cfu/g with commercial yogurt starter YC-Xll for yogurt preparation. During fermentation and storage time, the pH value, viscosity, syneresis, the viable count of S. thermophilus, L. delbrueckii subsp, bulgaricus and Lb. casei Zhang were determinated. The results showed that there was no significant differences （p〈0.05） in the yogurt samples with inoculation of Lb. casei Zhang about the pH value and the viable amount of S. thermophilus and L. delbrueckii subsp, bulgaricus compared to the control group. After 6 hours fermentation, there was no significant correlationship among all the analyses index （p〈0.05）.
During the 21 days storage, compared to the control yogurt sample, the pH value, viscosity, syneresis and the viable count of S. thermophilus was not significant differences （p〈0.05） for yogurt samples inoculated with Lb. casei Zhang, but the viable number of L. delbrueckii subsp, bulgaricus was significantly lower than the control sample （p〈0.05）. With the inoculation 2×10^6, 1×10^7 cfu/g of Lb. casei Zhang, the correlation between pH value and viscosity was significant positive （p〈0.05）, with the inoculation 4×10^6 cfu/g of Lb. casei Zhang, there was a significantly negative correlation （p〈0.05） between viscosity and syneresis, pH value and the viable count of Lb. casei Zhang.
出处
《乳业科学与技术》
2008年第4期151-156,共6页
JOURNAL OF DAIRY SCIENCE AND TECHNOLOGY
基金
"十一五"国家科技支撑计划(No.2006BAD04A00)
国家高技术研究发展计划(863计划
No.2006AA10Z345)
