提高郫县豆瓣甜瓣子品质的工艺条件优化

以郫县豆瓣生产过程中分离到的米曲霉（Aspergillus oryzae）、黑曲霉（Aspergillus niger）、根霉（Rhizopus）为出发菌种，以感官评价和氨基酸态氮及综合酶活力为评价指标，筛选出功能米曲霉（Aspergillus oryzae）SICC3.1083和SICC3.930进行提高甜瓣子品质研究。通过单因素试验，筛选出混合种曲比例、发酵温度、盐分3个显著影响因素，采用响应面法优化混合种曲发酵工艺条件。结果表明，最佳发酵工艺为米曲霉SICC3.1083和SICC3.930质量比1.0∶1.0、发酵温度40 ℃、发酵时间25 d、盐分12%。在此优化工艺条件下，甜瓣子感官评分为88分，氨基酸态氮含量为0.78 g/100 g，比优化前分别提高了17%和20%，感官评分和理化指标均优于传统发酵工艺。

Optimization of process conditions for improving quality of Pixian Douban sweet bean petals

Taking Aspergillus oryzae, Aspergillus niger and Rhizopus isolated from production process of Pixian Douban as the starting strains, and using sensory evaluation, amino acid nitrogen content and comprehensive enzyme activity as evaluation indexes, the functional A. oryzae SICC3.1083 and SICC3.930 were screened to improve the quality of sweet bean petals. Three significant influencing factors were selected by single factor tests, including the mixed koji ratio, fermentation temperature and salt content, and the fermentation process conditions of mixed koji were optimized by response surface methodology. The results showed that the optimum fermentation conditions were as follows: A. oryzae SICC3.1083 and SICC3.930 ratio 1.0∶1.0, temperature 40 ℃, time 25 d, and salt content 12%. Under the optimal conditions, the sensory score of sweet bean petals was 88 points, and the amino acid nitrogen content was 0.78 g/100 g, which was 17% and 20% higher than that before optimization. The sensory scores and physicochemical indexes were better than those of traditional fermentation process.