该研究对比分析了1种黑豆酱油和4种黄豆酱油中总酚、总黄酮、色深物质、氨基酸态氮、无盐固形物、还原糖、总糖、总酸和游离氨基酸等成分的含量及两类酱油的DPPH自由基清除能力、ABTS自由基清除能力、还原力和金属离子螯合能力。此外，采用相关性分析、聚类分析和主成分分析法分析了5种酱油的抗氧化活性成分与抗氧化活性之间的内在联系。结果表明，除氨基酸态氮、无盐固形物、游离氨基酸外，黑豆酱油的其他6种活性成分含量均显著高于其余4种黄豆酱油（p<0.05）；除金属离子螯合能力外，黑豆酱油的其他3种抗氧化活性均显著高于其余4种黄豆酱油（p<0.05）；相关性分析结果表明酱油中总酚、总黄酮和色深物质是造成5种酱油抗氧化活性存在显著差异的主要原因，聚类分析结果和主成分分析结果均表明黑豆酱油的综合品质高于其余4种黄豆酱油。因此黑豆酱油的综合品质显著高于其余4种黄豆酱油。上述研究结果可为黑豆酱油抗氧化活性的深入研究和消费者选择合适的酱油提供数据支撑和科学依据。

Total phenol, total flavonoid, dark color substance, amino acid nitrogen, salt-free solid, reducing sugar, total sugar, total acid, and free amino acid contents in a black soybean sauce and four other kinds of soy sauces were compared. In addition, DPPH and ABTS radical scavenging activity, reducing power, and metal ion-chelating activity of the selected soy sauces were comparatively analyzed. Correlation, cluster, and principal component analyses were performed to elucidate the internal relationship between antioxidant substances and antioxidant activity in the five soy sauces. The contents of six active ingredients, except for amino acid nitrogen, salt-free solid, and free amino acids, were significantly higher in the black soybean sauce than in the other four kinds of soy sauce (p<0.05). Furthermore, except for metal ion chelation, the antioxidant activity was significantly higher in the black soybean sauce than in the other four soy sauces (p<0.05). Correlation analysis showed that total phenols, total flavonoids, and dark color substances were the main components responsible for the significant difference in antioxidant activity among the five soy sauces. Cluster and principal component analyses indicated that the comprehensive quality of the black soybean sauce was significantly higher than that of the other four kinds of soy sauce. The findings provide supportive data and a scientific basis for further research on the antioxidant activity of black soybean sauce and will help consumers select an appropriate soy sauce.

国家自然科学基金项目（32071471）；阳西市科技创新战略专项（SDZX2021030）；中山市科技发展专项（2018A1007）