山药无糖酸豆奶的制备及降血脂功能研究

Preparation of Chinese yam sugar-free soybeanyogurt and analysis of its antihyperlipidemicrole

在豆奶中添加山药提取物和功能性甜味剂,控制乳酸菌可代谢糖含量制备一种具有降脂功效、后发酵质量稳定的无糖酸豆奶。采用筛选菌株,确定发酵剂;比较不同酸度下制品感官质量的变化,探讨后发酵质量的控制方法;以正交试验对配方优化;以高脂饲料建立高血脂大鼠模型,制品为干预饲料,了解制品对模型大鼠血脂的影响。结果表明:最佳工艺为豆奶75.6%,山药提取物12%,鲜牛奶5%,麦芽糖醇5.9%,嗜热链球菌H菌株发酵剂1%,保加利亚乳杆菌LB菌株发酵剂0.5%,配料接种后于42℃发酵10h。制品口感好,粘度好,后发酵酸度变化小,不产生涩味,质量稳定,对大鼠血清总胆固醇(TC)、甘油三酯(TG)水平均有显著降低作用,效果随剂量增大而增大,并显示添加山药提取物增效显著。本研究所确定生产工艺可较好地解决酸豆奶后发酵引起质量不稳定的问题,制品对高血脂大鼠的血脂具有很好的降低作用,可作为糖尿病人和高血脂病人的功能性食品来开发生产。

By supplementation of Chinese yam extracts and the functional sweetener agent to the soybean milk,and controlling the content of fermenting sugar for lactic acid bacteria,the present study is designed to develop a kind of lipid lowering,sugar-free soybean yoghurt with stable post-fermentation quality.The study was performed by screening the bacteria strains for fermentation firstly,followed by controlling the fermentation quality by evaluation the sensory changes of the product with different pH,then the formula was optimized through orthogonal test,finally the effect of the product（used as intervention feed） on the serum lipid was investigated by using high serum lipid model rats established by high lipid feed.The results showed the desirable recipe for the product was soybean milk 75.6%,Chinese yam extraction 12%,fresh milk 5%,maltitol 5.9%,Streptococcus thermophilus H 1% and Lactobacillus bulgaricus 0.5%.The mixture was then incubated at 42 ℃ for 10 hours.The resulted product tastes well but with no bitter flavor,and it posses appropriate viscosityand stable post-fermentation quality.The product significantly reduced the serum total cholesterol（TC）,triglyceride（TG）,low-density lipoprotein（LDL-C） levels of model rats,and the above effects were increased along with the increase of the dosage applied.The results also indicated that supplementation with yam extracts can significantly improve this kind of effect.The techniques developed in this study can solve the unstable quality problem associated with fermentation.The product also has the potential to decrease the blood lipid level in rats.It can be used as functional food for diabetes and high cholesterol patients.