霉菌纯种制曲豆豉在传统后发酵中的成分变化及其与生物胺相关性的研究

Changes in relevant components of mold starter-making Douchi during traditional post-fermentation and their correlations with biogenic amines

以大豆为原料,总状毛霉、米曲霉沪酿3.042分别纯种制曲,研究豆豉在"传统后发酵"中有关成分变化及其与生物胺的相关性。结果表明,此过程中豆豉水分基本稳定,总酸、氨基酸态氮和游离氨基酸先增加后稳定,pH先下降后稳定。对照组无脱羧酶活力但有少量的4种生物胺;曲霉组有鸟氨酸与苯丙氨酸的脱羧酶活力,生物胺种类由腐胺、2-苯乙胺、亚精胺和精胺减少为腐胺和2-苯乙胺;毛霉组有鸟氨酸和酪氨酸的脱羧酶活力及腐胺、亚精胺和酪胺。后发酵期间,曲霉和毛霉组总生物胺分别增加3.05、3.40倍,但前者含量更高。苯丙氨酸与2-苯乙胺呈弱相关,精氨酸与亚精胺、精胺呈极显著负相关(P<0.01);除水分外,pH、总酸、氨基酸态氮都与检出的生物胺显著相关(P<0.05)。

Soybean was used as raw material. Mucor racemosus and Aspergillus oryzae 3.042 were individually used to make pure starter to produce Douchi. Changes in related components and their correlations with biogenic amines were determined during traditional post-fermentation process. The results showed that during traditional post-fermentation process, the moisture content of Douchi remained stable. Contents of total acids, amino acid nitrogen, and related free amino acids increased at the beginning and then stabilized, while the pH decreased first and kept stable later. Decarboxylase activity was not detected but a small amount of 4 biogenic amines were detected in the control group. Activities of ornithine decarboxylase and phenylalanine decarboxylase were detected in Aspergillus oryzae group, and biogenic amines types decreased from 4 (apropamine, 2-phenylethylamine, imine and spermine) to 2 (aproamine and 2-phenylethylamine). In the Mucor racemosus group, activities of ornithine decarboxylase and tyrosine decarboxylase were detected, and it contained putrescine, spermidine, and tyramine. Total biogenic amines in Aspergillus and Mucor groups increased by 3.05 and 3.40 times, respectively, but the former content was higher. The correlation analysis showed that there was a weak correlation between phenylalanine and 2-phenylethylamine, while arginine was extremely negatively correlated with spermidine and spermine ( P <0.01). Besides, except for moisture content, pH, total acids, and amino acid nitrogen content were significantly correlated with detected biogenic amines ( P <0.05).