Analysis of Isoflavones and Phenolic Compounds in Korean Soybean [Glycine max (L.) Merrill] Seeds of Different Seed Weights

• Published in: Journal of agricultural and food chemistry 2008-04, Vol.56 (8), p.2751-2758
• Main Authors: Lee, Sun-Joo, Kim, Jong-Jin, Moon, Hyung-In, Ahn, Joung-Kuk, Chun, Sel-Cheol, Jung, Woo-Suk, Lee, Oh-Kyu, Chung, Ill-Min
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Chemical Composition of Foods/Feeds; chemical constituents of plants; Chromatography, High Pressure Liquid; cultivars; food composition; Food industries; Fruit and vegetable industries; Fundamental and applied biological sciences. Psychology; geographical variation; Glycine max; Glycine max - chemistry; HPLC; isoflavones; Isoflavones - analysis; Korea; phenolic acids; phenolic compounds; Phenols - analysis; seed weight; Seeds - anatomy & histology; Seeds - chemistry; Soybean; soybeans; weight
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf073153f

The seeds of 322 Korean soybean varieties were collected from six different cultivated sites in Korea and classified into three groups based on the 100-seed weight as small, medium, and large. Seeds were analyzed for their concentrations of isoflavones and phenolic compounds. The total average isoflavones in soybean cultivated at Iksan (2.840 µmol g−1) and phenolic compounds in soybean grown at Yeoncheon (9.216 µmol g−1) and Iksan (9.154 µmol g−1) were significantly different (p < 0.05). In small and medium seeds of soybeans cultivated at Yeoncheon, Yesan, and Milyang high levels of isoflavones were obtained, whereas soybeans grown in Chuncheon showed the lowest isoflavone concentrations. However, isoflavone concentrations in the large seeds of soybean cultivated at Chuncheon showed the highest level. The soybean cultivated at Yeoncheon had high levels of phenolic compounds in small, medium, and large seeds, whereas the soybean grown at Chuncheon had the lowest. On the other hand, the phenolic concentrations of large soybean cultivated at Milyang were the least. At Yeoncheon, Yesan, and Milyang, the total isoflavone and phenolic compounds levels related to their seed size was significantly different (p < 0.05), whereas in the soybean of different sizes cultivated at Chuncheon, the relationship to their seed size was not significantly different. The relationships of total isoflavones and phenolic compounds of small and medium soybean seeds were significantly higher than that of large soybean seeds. The hydroxybenzoic acid group in all sizes of seeds cultivated at six sites in Korea was the major phenolic compound, followed by flavonoid and hydroxycinnamic acid. The total isoflavone concentration was positively correlated with acetylglycoside and negatively correlated with malonylglycoside in the small soybean seeds cultivated at Yeoncheon. In medium soybean seeds cultivated at Yeoncheon, a significantly positive correlation was found between acetylglycoside and glycoside, between aglycone and glycoside, and between aglycone and acetylglycoside, whereas a significantly negative correlation was shown between malonylglycoside and glycoside, between acetylglycoside and malonylglycoside, and between aglycone and malonylglycoside. In large soybean seeds cultivated at Chuncheon, significantly positive and negative correlations were similar to those of medium seeds. The results presented here can improve the understanding of the relationships among the concentratio