酵母微胶囊固定化技术的优化及其在青稞酒发酵中的应用研究

Optimization of yeast microcapsule immobilization technology and its application in the fermentation of highland barley wine

为确保青稞酒产品质量的稳定性,以海藻酸钠-壳聚糖(AC)为原料,采用包埋法制备酵母微胶囊。通过扫描电子显微镜(SEM)观察到酵母微胶囊形态呈圆形,表面存在孔状结构。傅里叶变换红外光谱仪(FTIR)分析表明粒径大小不影响其内部结构。以酵母微胶囊的硬度为评价指标,得到酵母微胶囊固定化最佳工艺条件为海藻酸钠添加量3%,氯化钙添加量4%,壳聚糖添加量0.8%,固化时间2 h,覆膜时间15 min。在此优化条件下制备的酵母微胶囊硬度为1615.54 g,颗粒呈球形,颜色为乳白色,结构完整。将其应用于青稞酒发酵,酒精度比对照组高0.08%vol,总糖与对照组无显著差异(P>0.05),而总酸含量比对照组低0.36 g/L。微胶囊固定化技术在应用中具有实际可操作性,对青稞酒品质的提升具有重要指导意义。

In order to ensure the quality stability of highland barley wine,yeast microcapsules were prepared by embedding method using alginate-chitosan(AC)as raw material.Scanning electron microscopy(SEM)showed that the yeast microcapsules were round and there were porous on the surface.Fourier transform infrared spectrometer(FTIR)analysis showed that the particle size did not affect the internal structure.Taking the hardness of yeast microcapsule as the evaluation index,the optimal technological conditions for immobilization of yeast microcapsules were as follows:sodium alginate addition 3%,calcium chloride addition 4%,chitosan addition 0.8%,curing time 2 h,and coating time 15 min.Under these optimal conditions,the hardness of the yeast microcapsule could reach 1615.54 g,the particle was spherical,the color was milky white,and the structure was complete.When it was applied to the fermentation of highland barley wine,the alcohol content of highland barley wine was 0.08%vol higher than that of the control group,the total sugar was not significantly different from that of control group(P>0.05),and the total acid content was 0.36 g/L lower than that of the control group.Microcapsule immobilized technology had practical maneuverability in application and had important guiding significance for improving the quality of highland barley wine.