复原乳代替鲜乳在奶啤发酵中的分析比较

Analytical Comparison of Reconstituted Milk instead of Fresh Milk in Milk Beer fermentation

摘要:

奶啤是经过乳酸菌、酵母菌先后两步发酵制成的新型发酵乳饮品。试验从理化性质、持水力、色度、粒度、质构、流变、扫描电镜、香气成分等方面分析了以复原乳为原料生产奶啤的可行性，与生鲜乳奶啤相比，以复原乳为原料制备的奶啤品质略有降低，但不显著（P>0.05）。复原乳奶啤的持水力降低了1.17%；明暗度L*值降低了24.8%；蛋白质粒径增加了15.3%；且香气与生鲜乳奶啤存在微小差异；流变分析说明随着剪切时间的延长，复原乳奶啤与生鲜乳奶啤表观粘度的变化趋势相同；扫描电镜显示其在微观结构方面也无显著差异；复原乳奶啤的感官评价分数为7.50，略低于生鲜乳奶啤；质构方面，复原乳奶啤的弹性相对于生鲜乳奶啤增加了8.92%，硬度、凝聚力等方面均无显著差异（P>0.05），说明这些差异可被消费者接受。通过此项研究证明了复原乳在一定程度上可代替鲜乳发酵奶啤，解决了奶啤制作过程中过度依赖鲜乳，但内地鲜乳不足且质量参差不齐的难题。

Abstract:

Milk beer is a new type of fermented milk beverage made by two-step fermentation of lactic acid bacteria and yeast. The feasibility of producing milk beer from reconstituted milk was analyzed in terms of physicochemical properties, water holding capacity(WHC) ,color, particle size, texture, rheology, scanning electron microscopy, and aroma composition, etc. The quality of milk beer prepared from reconstituted milk was slightly reduced compared with that of fresh milk beer, but it was not significant (P>0.05). The water holding capacity of reconstituted milk beer decreased by 1.17%; the brightness L* value decreased by 24.8%; the protein particle size increased by 15.3%; and there was a small difference in aroma with that of raw milk beer; rheological analysis showed that with the extension of shear time, the apparent viscosity of reconstituted milk beer and raw milk beer had the same trend of change; scanning electron microscopy showed that there was no significant difference in the microstructure of the reconstituted milk beer; and the sensory evaluation score of the reconstituted milk beer was 7.50, which was slightly lower than that of raw milk beer; in terms of texture, the elasticity of reconstituted milk beer increased by 8.92% compared with that of raw milk beer, and there were no significant differences in hardness and cohesion (P>0.05), which indicated that these differences could be accepted by consumers. This study proves that reconstituted milk can replace fresh milk fermented milk beer to a certain extent, and solves the problem of over-reliance on fresh milk in milk beer making, but the fresh milk in the mainland is insufficient and the quality varies.