残次裂枣枣酒发酵菌相变化及工艺比较分析

摘要

以残次裂枣为原料,采用直接发酵工艺和蒸煮后发酵工艺进行酿酒.对直接发酵工艺过程中微生物的菌相变化进行研究,比较2种发酵工艺对枣酒品质的影响.结果表明,残次裂枣原料中有害微生物主要包括霉菌和大肠杆菌.在发酵过程中,第3天时大肠杆菌的存活量降至0.03 MPN/mL以下,第6天时检测不到霉菌.发酵后期酒液中的微生物主要为酵母菌,还有少量乳酸菌和醋酸菌.直接发酵工艺得到的枣酒酒精体积分数、Vc质量分数、多酚质量浓度分别为8.9％、45.8 μg/g、1.184 g/L;蒸煮后发酵工艺所得的枣酒酒精体积分数、Vc质量分数、多酚质量浓度分别为7.8％、47.7 μg/g、1.153 g/L.与蒸煮后发酵工艺相比,直接发酵工艺得到的枣酒中的,乙酸乙酯、乳酸乙酯、己酸乙酯质量浓度较高,杂醇油质量浓度较低,甲醇质量浓度符合国家标准(＜0.4 g/L).因此,直接发酵工艺得到的枣酒品质较好.%In this research, defective jujube was used to produce wine with two different fermentation processes. One technology was called direct fermentation technique, in which jujube was used for fermentation directly without steaming treatment. And in the other technique, jujube was steamed before fermentation. Microbial flora change was studied during fermentation process of jujube in the first technique. Several quality parameters of the wine produced by the two methods were compared, which include the content change of phenol in the fermentation process, the contents of alcohol, Vc, metha-nol, and esters in the final product. The results showed that the main microbial species in jujube after harvest were mold and E. Coli. On the third day of fermentation, the amount of E. Coli reduced to less than 0. 03 MPN/mL. On the sixth day of fermentation, mold could not be detected. At the end of the fermentation, the main microorganisms in the wine were yeast and a small quantity of lactic acid bacteria and acetic acid bacteria. The contents of alcohol and Vc in the wine produced by direct fermentation technique were 8. 9% and 45. 8 jug/g. And the contents of them in the wine made by the second technology were 7.8% and 47. 7 jug/g. The contents of polyphenol, ethyl acetate, ethyl lac-tate, and ethyl caproate in the wine produced by direct fermentation technology were higher and the content of fusel oil was lower than that produced by the other technique. The contents of methanol in the wine produced by both the fermentation technologies were lower than 0. 4 g/L which was the max-imal value regulated by Chinese National Standard. So, the property of wine produced by direct fermentation technique was better than that produced by another technique.