茯苓酸奶制作最佳工艺的优化探索

目的]优化茯苓酸奶的制作工艺。方法]在单因素试验的基础上进行正交试验,探讨茯苓多糖液体发酵条件,确定茯苓酸奶制作的最佳工艺。结果]茯苓多糖最佳液体发酵条件为:26℃,150 r/min,培养基初始pH值5.6,接种6%的菌龄为2 d的茯苓菌,摇瓶振荡培养7 d,发酵液中茯苓多糖含量为6.91 mg/ml。各因素对茯苓酸奶发酵质量的影响由大到小依次为:混合液(奶粉、发酵液、水)的构成质量>发酵温度>接种量>糖浓度。结论]茯苓乳酸制作的最佳工艺为:奶粉∶发酵液∶水=1∶1∶7,混合发酵剂(嗜热链球菌∶保加利亚菌=1∶1)接种量6%,糖浓度6%,发酵温度40℃,发酵6 h后后熟12~24 h,制取的酸奶品质最好,兼具茯苓发酵液的香味与酸奶的风味。

Exploration on Optimization of the Technology of Making Poria cocos Yoghurt

Objective] This study aimed to optimize the technology for making Poria cocos yoghurt.Method]Based no the single factor test the orthogonal test was conducted to discuss the condition of fluid fermentation of P.cocos polysaccharides and confirm the optimum technology for making P.cocos yoghurt.Result]The optimum conditions for liquid fermentation of P.cocos polysaccharides were: 150 rpm,26 ℃,initial pH 5.5 in medium,inoculating 6% P.cocos strain at 2 d age,shake culture for 7 d and the content in fermentation liquid of about 6.91 mg/ml.The effect of each factor on the fermentation quality of P.cocos yoghurt in order was mixed liquid(milk∶fermentation liquid∶water) > fermentation temperature > inoculation amount > sugar concn.Conclusion] The optimum technology for making Poria cocos yoghurt was as follows∶milk∶fermentation liquid∶water=1∶1∶7,inoculation amount of mixed fermenting agent(Streptococcus thermophilus∶Lactobacillus bulgaricus=1∶1) of 6%,sugar concn.of 6%,fermentation temperature of 40 ℃,and after-ripening for 12-24 h after fermentation for 6 h,by which,the produced P.cocos yoghurt had best quality,good taste,with both Poria cocos cultivated broth flavor and special yogurt flavor.