复合乳酸菌发酵降低蛋黄液中胆固醇的工艺优化

为降低蛋黄液中胆固醇含量，选择出降胆固醇效果较好的3 种菌作为复合发酵菌种，将复合菌株接种到蛋黄液中，于恒温培养箱中培养，用直接皂化-比色法探讨了复合乳酸菌对蛋黄液中胆固醇降低率的影响，利用正交试验优化最佳发酵工艺参数。结果表明，最佳工艺条件为发酵温度40 ℃、发酵时间24 h、接种量3%、牛胆盐质量浓度3 g/L、混合菌种（嗜热链球菌、嗜酸乳杆菌、双歧杆菌）菌液体积比1∶2∶1，在此条件下，可使蛋黄中胆固醇降低率达31.5%。

Optimization of Fermentation Conditions for Cholesterol Reduction in Egg Yolk by Mixed Lactobacillus Culture

Egg yolk was inoculated with a mixed culture of three strains with high cholesterol-reducing capacity and kept
in a thermostatic oven in order to maximize cholesterol reduction. Direct saponification-colorimetry method was used to
measure the reduction rate of cholesterol. The fermentation conditions were optimized using an orthogonal array design as
follows: fermentation temperature, 40 ℃; fermentation time, 24 h; inoculum amount, 3%; bile salt concentration, 3 g/L; and
the proportion of mixed strains, 1:2:1 (Streptococcus thermophilus:Lactobacillus acidophilus:Bifidobacterium). Under these
conditions, the cholesterol in egg yolk was reduced by 31.5%.