海藻酸钙固定化乳酸菌连续化预发酵生产酸奶

Study on Continuous Pre-fermentation for Production of Yogurt by Encapsulated Lactic Acid Bacteria in Calcium Alginate Immobilized System

将唾液链球菌嗜热亚种、德氏乳杆菌保加利亚亚种分别固定化于海藻酸钙形成的液芯包囊中,在一个连续搅拌反应器中对牛奶进行连续化接种,预发酵生产酸奶。试验结果表明,随着温度的升高和pH值的降低,凝乳时间都呈缩短的趋势。生物反应器的搅拌速度对稀释率影响显著,随着搅拌速度增加,稀释度明显下降。温度、pH值和搅拌速度对连续接种牛奶的接种量影响不显著,预发酵牛奶的接种量(总细菌数)均达到了108CFU/mL。

Two strains of lactic acid bacteria （ Lactobacillus delbruekii ssp. Bulgaricus and Streptococcus salivarius ssp. Thermophilus ）were immobilized separately in liquid-core alginate capsules and used for continuous inoculation- prefermentation of milk for yoghurt production in a stirred tank reactor. The result showed that the coagulum time was shortened with the increase of temperature under the lower level pH. The effect of stirring speed on the dilution rate was significant. The dilution rate decreased as stirring speed increased. The inoculation of pre-fermented milk （total number of bacteria） were unaffected by pre-fermentation temperature, pH and stirring speed. In all cases, pre-fer- mented milk was inoculated at 10^8 CFU/mL.