Effect of fermented Rhus verniciflua stokes extract on liver function parameters in healthy Korean adults: a double-blind randomized controlled trial.

BACKGROUND: Fermented Rhus verniciflua Stokes extract (FRVE) reported an anti-hepatic lipidemic property mediated by the upregulation of AMP-activated protein kinase (AMPK) in cell and animal models. However, it remains unclear whether there is an effect of FRVE on liver disease-related parameters and serum lipid levels in humans. We investigated the effects of FRVE intake for 12 weeks on liver disease-related parameters and serum lipid profiles in Korean adults. METHODS: A randomized, double-blind, placebo-controlled study was conducted among 79 subjects. An aqueous extract of fermented Rhus verniciflua Stokes that was filtered and fermented was prepared. For 12 weeks, the test group (n = 39) consumed two capsules of FRVE (main components: fustin 129 mg and fisetin 59 mg) once daily. The control group (n = 40) consumed two placebo pills (main component: lactose 627.0 mg) once daily. A 1:1 randomization of control and test was performed using computer-generated randomization. Both before and after FRVE intake, anthropometric parameters, liver function-related parameters, and clinical laboratory parameters were measured. The effects between the test and control groups were compared using the Mann-Whitney U test and independent t-test, and the difference between baseline and follow-up values was compared using Wilcoxon rank-sum test and paired t-test. RESULTS: There was no significant difference when comparing the change values of liver disease-related parameters and serum lipid profiles in between groups. CONCLUSIONS: In our study, we did not confirm the significance in liver function parameters and serum lipid profiles. TRIAL REGISTRATION: The study protocol was registered in the Clinical Research Information Service (CRIS: https://cris.nih.go.kr/cris/index.jsp ) under number KCT0005687. Registered on 2 December 2020.

Biogenic amine production of makgeollis with controlled alcohol concentrations.

In this study, we examined the effects of controlling the alcohol concentration of non-sterilized makgeolli on the levels of biogenic amines (BAs) as an indicator of hygiene. Makgeollis were prepared at four different alcohol concentrations (5.73-13.17%) and stored at 20 °C for 30 days. Makgeollis with low alcohol contents (5.73-8.07%) showed significant variations in alcohol and BA concentrations, volatile acid contents, pH, total acidity, and lactic acid bacteria counts under these conditions. In contrast, makgeollis with alcohol contents of 11.47% or more showed no significant changes. In low-alcohol makgeollis, the produced BA was mostly tyramine, which increased dramatically on day 20 of storage in makgeolli containing 5.73% alcohol and on day 30 in makgeolli containing 8.07% alcohol. These results indicated that makgeolli could be stored for long periods at high temperatures, such as those during summer, by controlling the alcohol concentration.

Effect of heat-treated Nuruk on the quality characteristics of aged Yakju.

Long-term aging of Yakju, a traditional Korean liquor made of rice and Nuruk (a fermentation agent), causes browning and odor and flavor development. This study investigated the effects of heat-treated Nuruk (50-80 °C, 30 min) on Yakju quality. The saccharogenic powers and glucoamylase, α-amylase, and carboxypeptidase activities were similar in non-heat-treated Nuruk and that treated at 50 °C. However, acidic protease and alcohol dehydrogenase decreased above 50 °C. The content of nitrogen-containing compounds was inversely proportional to the heat-treatment temperature. Compounds that cause off-flavors decreased at 50-60 °C, but increased at 70-80 °C, whereas compounds that provide fragrance increased at 50-60 °C. Sensory evaluation indicated that bad taste attributes were higher in Yakju produced using non-heat-treated Nuruk. Therefore, heat treatment of Nuruk at 50 °C can be adopted as a method for improving Yakju quality, as enzymatic activities that affect color, aroma, and taste are regulated.

Characterization of Acetobacter pomorum KJY8 isolated from Korean traditional vinegar.

Acetobacter sp. strains were isolated from traditional vinegar collected in Daegu city and Gyeongbuk province. The strain KJY8 showing a high acetic acid productivity was isolated and characterized by phenotypic, chemotaxonomic, and phylogenetic inference based on 16S rRNA sequence analysis. The chemotaxonomic and phylogenetic analyses revealed the isolate to be a strain of Acetobacter pomorum. The isolate showed a G+C content of 60.8 mol%. It contained LL-diaminopimelic acid (LL-A2pm) as the cell wall amino acid and ubiquinone Q9 (H6) as the major quinone. The predominant cellular fatty acids were C18:1w9c, w12t, and w7c. Strain KJY8 grew rapidly on glucose-yeast extract (GYC) agar and formed pale white colonies with smooth to rough surfaces. The optimum cultivation conditions for acetic acid production by the KJY8 strain were 20°C and pH 3.0, with an initial ethanol concentration of 9% (w/v) to produce an acetic acid concentration of 8% (w/v).