吸附-包埋复合固定化酵母在啤酒连续后发酵中的应用研究

Application of Immobilized Yeast Treated by Adsorption-embedment Method in Continuous Fermentation of Beer

以浓度为2%的海藻酸钠溶液与浓度为4%的氯化钙溶液为包埋剂,以经预处理的山毛榉木片为吸附剂,选择所配制的不同浓度的吸附剂和包埋剂为载体对酵母细胞进行复合固定化处理,利用所制备的固定化酵母进行啤酒连续后发酵,对不同浓度载体的固定化效果及所产生的熟啤酒的主要指标进行分析和比较。结果表明,由所制备的150 mL海藻酸钠溶液与50 mL山毛榉木片吸附剂复合而成的载体D固定酵母数量最多,生物载荷量高达2.17×1010个/g,且牢固程度最优;载体后酵所获得的啤酒中双乙酰含量差异显著(p<0.05),载体D方案所生产的啤酒中双乙酰的含量最低;在风味物质中,乙醛、甲酸乙酯、正丙醇、异丁醇、乙酸乙酯的差异显著(p<0.05),其他风味物质的差异不显著(p>0.05)。

With 2 % sodium alginate and 4 % calcium chloride as embedding materials and with pretreated beech wood chip as adsorbent, adsor- bent and embedding agents of different concentrations were used as yeast carriers to immobilize yeast cells, the immobilizing effects of carriers of different concentrations were compared, and the main indexes of beer from continuous secondary fermentation by these carriers were compared with beer from traditional secondary fermentation. The results suggested that, when the cartier was 150 mL sodium alginate and 50 mL beech wood chip, the number of immobilized yeast was the largest up to 2.17xl0t^aJg and the stability of the immobilized yeast was the best. There was significant difference in the content of diacetyl （ p 〈 0.05） between beer from continuous secondary fermentation and beer from traditional fermen- tation. Such difference was also significant in some flavoring substances such as ethyl formate, ethyl acetate, n-propanol, isobutanol, and isoamyl （p 〈 0.05）, however, the difference was not significant in the rest of flavoring substances （p 〉 0.05）.