双歧杆菌与乳酸菌混合发酵胡萝卜汁牛乳饮料的工艺研究

Studies on the Technology of Carrot Juice Yoghurt Fermented by Bifidobacteria and Lactobacteria Together

以从健康人体中选育出的发酵活力高、耐氧性和抗逆性强的优良发酵菌株长双歧杆菌(Blm)作为主要试验菌株,以乳酸菌保加利亚乳杆菌(L.b-DR)和嗜热链球菌(S.t-3)作为辅助菌株,研究了接种量及菌种配比、基质起始pH值、发酵温度、氧气等因素对双歧杆菌与乳酸菌混合发酵胡萝卜汁牛乳饮料时,对凝乳时间、活菌含量、pH值和产品感官风味的影响。利用正交试验优化并确定了Blm与乳酸菌混合发酵的最佳工艺条件,即在胡萝卜汁牛乳培养基(25%胡萝卜汁和5%蔗糖)中,总接种量3%(3×107cfu/mL),其菌种配比为Lb-DR∶St-3∶Blm=1∶1∶1,基质起始pH值7.0,发酵温度39℃,有氧条件发酵。产品凝乳时间在3.33 h,pH值为4.5左右,总活菌数可达1×109cfu/mL以上,橙黄色,组织状态致密细腻,无乳清析出。对该产品的工艺条件探究,为开发其它功能性益生菌乳制品提供了新的思路和方法。

Bifidobacteria （Blm） which were isolated from healthy people were taken as main experiment strains, which are oxygen-resistant, adversity-resistant and highly activity. Lactoacillus bulgaricus and Streptococcus therrnophillus were also added as assistant strains. Inoculation, the ratio of strains, initial pH, and fermented temperature were studied on the effects of curd time, the viable cell numbers, pH value, flavor and sense of product in this paper. By doing orthogonal experiment, the optimal technique of carrot juice yoghurt fermentedwith Elm ＆ Lactobacillus together was as follows： overall inoculation 3% （3 × 10^7 cfu/mL）, ratio of strains （Lb-DR ： St-3 ： Blm） equals 1 ： 1 ： 1, initial pH 7.0, fermented temperature 39℃ , and fermented with oxygen. With the optimal technique, the curd time was at 3.33h, pH was 4.5, and the viable cell numbers reached more than 1 × 10^9 cfu/mL with orange , exquisite texture and no whey. The study provided new ideas and methods for studying other probiotic yoghourt products.