Weon-Taek Seo’s research while affiliated with Gyeongnam National University of Science and Technology and other places

For the production of Korea traditional cereal wine makgeolli, a rice fermentation starter nuruk was Rhizopus oryaze CCS01 commercial nuruk. The carbohydrate content of rice nuruk was higher, the levels of moisture, ash, crude protein, and crude fat were lower. In particular, the saccharifying activity of rice nuruk was 2.2 times higher than commercial nuruk. pH, alcohol, and viable yeast cells of makgeolli made rice nuruk were higher than those of makgeolli made commercial nuruk. In contrast, the levels of acidity, , viable lactic acid bacteria (LAB) cells, and browning of makgeolli made rice nuruk were lower than those of makgeolli made commercial nuruk, the alcohol content of glutinous rice (GUR) makgeolli made rice nuruk higher other samples. These results suggest that rice nuruk R. oryzae CCS01 make new type cereal makgeolli.

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.

The potential probiotic of a total of 15 Bacillus species isolated from Korean soybean paste (doenjang) was evaluated. Among those tested, the CSY191 and CSY388 strains were selected as probiotic bacteria due to their acid and bile tolerance, respectively. These strains were classified as Bacillus subtilis based on morphological, physiological, and chemotaxonomic features as well as on phylogenetic analysis based on their 16S rDNA sequences. These strains CSY191 and CSY388 showed a significant survival with rate range of 30.0 to 58.3% and of 31.0% to 58.1%, respectively, under artificial gastric acidic conditions at pH 3.0. These CSY191 and CSY388 strains appeared to have high antimicrobial activity against Salmonella Typhimurium, Bacillus cereus and Listeria monocytogenes. Also, methanol extractions (surfactin-like compounds) of strain CSY191 and strain CSY388 activated RAW264.7 microphages and induced the production of nitric oxide (NO) in a concentration-dependent manner, respectively. Therefore, strain CSY191 and strain CSY388 can be used as potential probiotics.

The purpose of this study was to investigate the phytochemical contents and biological activities, including -glucosidase inhibitory activity and antioxidant activity, from the fruits of Elaeagnus multiflora using different solvent systems. The 50% ethanol extract of this species showed the most potent -glucosidase inibitory activity (88.5%) at a concentration of 1 mg/mL. Moreover, this extract also displayed the strongest antioxidant activity in each assay, showing 96.3% in DPPH scavenging activity, 98.2% in ABTS scavenging activity, and 2.5% in reducing power. The highest total phytochemical contents, including flavan-3-ols, phenolic acids, and flavonoids, were observed in the 50% ethanol extract. Interestingly, flavan-3-ols (3.150 mg/g) were detected at a significantly higher total content than those of phenolic acids (0.380 mg/g) and flavonoids (not detected). Additionally, the contents of individual phytochemicals showed remarkable differences, especially the epicatechin gallate (2.008 mg/g) and gallic acid (0.099 mg/g), which were the predominant constituents of each phytochemical type. Therefore, our results suggest that the 50% ethanol extract of E. multiflora fruits has strong biological activities, which are correlated with high phytochemical contents.

Lactic fermented dongchimi naengmyeun broth which has enhanced antioxidative activity was developed. During lactic fermentation of dongchimi naengmyeun broth at , changes of total lactic acid bacteria, pH, acidity, soluble phenolics, and anthocyanins were investigated. After 72 h of fermentation, the stronger antioxidant activities were observed in dongchimi naengmyeun broth supplemented with purple sweet potato than those of control dongchimi naengmyeun broth which showing 96.80% in DPPH radical scavenging activity, 100.82% in scavenging activity, 7.77 in reducing power, and 6.89 in ferric reducing/antioxidant power, respectively. These high antioxidant activities related with higher contents of soluble phenolics and anthocyanins in dongchimi naengmyeun broth supplemented with purple sweet potato. The results suggest that the making of functional dongchimi naengmyeun broth by using high soluble phenolics and anthocyanins supplements such as purple sweet potato powder was possible.

In this study, the characteristics of the lactic fermentation of gamju manufactured using a medicinal herb decoction were assessed. A bacterial strain, LAB19, which is used for the induction of lactic fermentation into gamju, was isolated from dried persimmon and identified as Leuconostoc mesenteroides on the basis of morphological, physiological, and chemotaxonomical features, and 16S rRNA sequencing analysis. After 60 hours of lactic fermentation with Leuconostoc mesenteroides LAB19 at , the gamju was determined to contain 141.3 g/L of reducing sugar, 5.33 g/L of acids, and 1.19 g/L of soluble phenolics. Approximately 90% of reducing sugar and 58% of acids were maltose and lactic acid, respectively. Free radical scavenging activities were retained at levels between 76.6 to 75.7% during the lactic fermentation of gamju.