响应面法优化复合益生菌发酵枸杞汁的工艺研究

Optimization of fermentation technology of Lycium barbarum juice with compound probiotics by response surface methodology

以宁夏枸杞干果为主要原料,利用复合益生菌进行发酵。通过单因素和响应面试验设计,分别考察菌种比例、料水比、接种量和发酵时间对发酵枸杞汁品质的影响。结果表明,最佳发酵条件为复合益生菌配比为植物乳杆菌∶肠膜明串珠菌∶嗜热链球菌∶保加利亚乳杆菌=3∶3∶2∶1,料水比(枸杞干果∶水)为1∶9(g∶mL),接种量5%,发酵时间8 h。发酵后测得发酵枸杞汁中的乳酸含量为432 mg/100 mL,活菌数为2.3×10^(8)CFU/mL,总糖含量为155 mg/100 mL,总黄酮含量为0.25 mg/100 mL,蛋白质含量为0.2 g/100 mL,感官评分达到96分;发酵枸杞汁颜色为鲜亮的橘红色,口感细腻柔和,发酵香气浓郁且具有枸杞特征滋味。

The dried Lycium barbarum in Ningxia was used as the main raw material and fermented by compound probiotics. The effects of strains ratio, solidliquid ratio, inoculum and fermentation time on fermented goji juice quality were studied by single factor test and response surface methodology. The results showed that the optimal fermentation condition was composite probiotics ratio Lactobacillus plantarum : Leuconostoc mesenteroides : Streptococcus thermophiles : and L. bulgaricus = 3:3:2:1, solid-liquid(dried goji : water) ratio 1:9(g:ml), inoculum 5%, and fermentation time 8 h. The lactic acid content in the fermentation broth was 432 mg/100 ml, the viable cell count was 2.3×108 CFU/ml, the total sugar content was 155 mg/100 ml, the total flavonoid content was 0.25 mg/100 ml, the protein content was 0.2 g/100 ml, and the sensory score reached 96. The color of the fermented L. barbarum juice was bright orange, the taste was exquisite and soft, the fermented aroma was strong, with characteristic taste of L. barbarum.