黑豆丹贝发酵前后香气、酚类物质及抗氧化活性分析

为了丰富丹贝品种并提高黑豆食品加工利用率,本试验以少孢根霉(Rhizopus oligosporus)发酵制备黑豆丹贝,测定其基本营养成分和香气成分,并分析不同发酵时间黑豆丹贝中麦角固醇、氨基酸态氮、10 kDa以下肽、总酚、总黄酮、原花青素含量及蛋白质水解度抗氧化活性的变化。结果表明,与未发酵样品相比,发酵后黑豆丹贝中灰分、粗脂肪含量无显著差异(P>0.05),水分、粗蛋白含量有显著变化(P<0.05);发酵后黑豆丹贝中共检出24种香气成分,较未发酵样品多14种,且发酵后新检出醛类、烃类和酯类三类香气成分;黑豆丹贝发酵过程中麦角固醇含量先上升后下降,在33 h达到最大值911.39 μg·g^-1; 发酵15 h氨基酸态氮、10 kDa以下肽含量和蛋白质水解度显著增加(P<0.05),最大值分别为0.87 g·100g^-1、335.60 mg·g^-1和29.43%。此外,发酵结束后黑豆丹贝的总酚、总黄酮、原花青素含量分别为2.23、0.70和2.22 mg·g^-1, 显著高于未发酵样品(P<0.05),且总酚、总黄酮、原花青素含量与抗氧化活性密切相关。本研究结果为黑豆丹贝的开发提供了理论依据。

Aroma,Phenols and Antioxidant Activities of Black Bean Tempeh Before and After Fermentation

In order to enrich the variety of tempeh and improve the utilization rate of black bean in food industry, the black bean was used as raw material to study the effect of fermentation with Rhizopus oligosporus on the basic nutritional and aroma components of black bean tempeh. The contents of ergosterol, amino acid nitrogen, degree of hydrolysis, peptides below 10 kDa, total phenols, total flavonoids, proanthocyanidins in black beans at different fermentation time and the antioxidant activities were also studied. The results showed that there was no significant difference in ash content and crude fat content before and after fermentation. The moisture content and crude protein content were significantly different(P<0.05)from those of the samples without fermentation. A total of 24 kinds of aroma components were detected in fermented black bean tempeh, 14 kinds more than that of unfermented samples, and three kinds of aldehyde, hydrocarbon and ester components were only found fermented samples. During fermentation, ergosterol content first increased and then decreased, reaching a maximum of 911.39 μg·g^-1 at 33 h. After 15 h, the contents of amino acid nitrogen, peptides below 10 kDa and degree of protein hydrolysis increased significantly (P<0.05), with the maximum values of 0.87 g·100g^-1, 335.60 mg·g^-1 and 29.43%, respectively. In addition, the total phenol, total flavonoids and proanthocyanidins contents of fermented black bean tempeh were 2.23 mg·g^-1, 0.70 mg·g^-1 and 2.22 mg·g^-1 respectively, which were significantly higher than those of before fermentation (P<0.05), and the contents of total phenol, total flavonoids and proanthocyanidins were closely related to antioxidant activity. The study provides theoretical basis for the development of black bean tempeh.