Seung-Ho Jeon’s research while affiliated with Sunchon National University and other places

Resveratrol is synthesized by the catalysis of resveratrol synthases (RS) in a limited number of higher plants. Resveratrol shows potential health-promoting properties, including as an antioxidant and in preventing cardiovascular diseases. Recently, resveratrol-enriched rice has been produced as a novel source of resveratrol. This study aimed to investigate the major agronomic characteristics of resveratrol-enriched rice, Iksan526 (I526) and compared them with those of a nontransgenic and commercial rice variety, Dongjin (DJ). Transgene (RS) integration was confirmed using Southern blot analysis, and homologous recombination was achieved after digestion with the SacI restriction enzyme. The phenotypic traits of I526 grown in Iksan were similar to those grown in Milyang but not similar to those grown in Suwon. In Suwon, I526 had slightly earlier heading dates [i.e., number of days from sowing to heading) and shorter culm lengths. When I526 was treated with 0.4% Basta in the seedling stage, no significant difference was observed among all the agronomic traits compared with nontreated I526; particularly, the culm length, panicle length, number of panicles per hill, 1,000 grain weight of brown rice, and brown rice yield of the Basta-treated rice were similar to those of the nontreated I526, regardless of their cultivation region. The resveratrol content of I526 grown in Suwon and Milyang was increased by 18% and 37%, respectively, than that of I526 grown in the Iksan area. Therefore, DJ and I526 are not significantly different in terms of major agronomic traits depending on variety/year and variety/cultivation region. The results indicated that I526 has the potential to become a commercialized variety in the near future.

The goal of this study was to evaluate the influence of various supplementary feeds on the chemical composition and production of bioactive substances in Protaetia brevitarsis larvae. The primary feed-oak-fermented sawdust-was supplemented with a variety of substances, including aloe, apple, banana, sweet persimmon (S. persimmon) and sweet pumpkin (S. pumpkin). Crude protein and fat content were the highest in the control and S. pumpkin group, respectively. Supplementary feeds increased the content of unsaturated fatty acids, except in the group receiving S. pumpkin, in which oleic acid was the most abundant (58.2%-64.5%). Free essential amino acids in larvae receiving supplementary aloe were higher compared with the control group except for Lys and His. Polyphenol and flavonoid contents and the antioxidant activities of ABTS and DPPH were higher in all treated groups compared with the control group. Although supplementary feeds led to a decreased crude protein content in the treated larvae when compared with the control group, these treatments generally improved the levels of unsaturated fatty acids and antioxidative activity. Therefore, we suggest that among the supplementary foods tested, aloe is a better resource for P. brevitarsis based on crude protein content, free amino acids and other bioactive compounds such as unsaturated fatty acids and antioxidants.

This study was done to examine the correlation between differential contents of antioxidants and their antioxidative activities in the seeds obtained from two sorghum cultivars (Nampungchal and Hwanggeumchal) according to harvest time post heading, and to understand the properties of the harvested seeds. The seeds were harvested every 5 days from 25-55 days post heading. Length, width, thickness, and morphological properties of the obtained seeds were increased in proportion to the harvest time. The weights per thousand grains, crude fat, and redness (a?) clearly changed depending on the harvest time. The grain weight and fat content showed the highest value at harvest time days 45 (HT 45). The seed coat lightness (L∗), crude protein, total polyphenol, flavonoid, and tannin in both cultivars were inversely proportional to the harvest time. In addition, ABTS and DPPH radical scavenging activities were also reduced in inverse proportion to the elapsed harvest time. Antioxidants including polyphenol, flavonoid, and tannin showed positive correlations with the antioxidative activities such as ABTS and DPPH activities, but antioxidants and their activities had no significant correlations between cultivars. We therefore propose that sorghum harvest is performed earlier to improve its antioxidative function.