• The Korean Journal of Mycology
• /
• v.46 no.3
• /
• pp.307-314
• /
• 2018

The goal of this study was to investigate the microbiological characteristics of the ethanol-producing wild yeast, Aureobasidium pullulans P-1, isolated from flowers growing near the Yedang reservoir, Chungnam province, Korea, and in addition, to optimize its fermentation ability for the production of Makgeolli. A. pullulans P-1 was oval-shaped, and formed ascospores and pseudomycelium. The P-1 strain was a halophilic and sugar tolerant yeast which grew in 15% NaCl and 50% glucose-containing yeast extract-peptone-dextrose media. The P-1 strain was also resistant to 20% ethanol. Changes of the physicochemical properties during Makgeolli fermentation by A. pullulans P-1 were investigated. A maximum of 8.45% ethanol was obtained when a mixture of cooked rice, 150% water, and 35% ipguk per cooked rice was fermented by 5% A. pullulans P-1 culture broth at $25^{\circ}C$ for 10 days. Antihypertensive angiotensin I-converting enzyme inhibitory activity in the Makgeolli ferment produced by A. pullulans P-1 reached a high of 71.1% after 10 days.

• Microbiology and Biotechnology Letters
• /
• v.43 no.2
• /
• pp.97-104
• /
• 2015

Vinegar is a widely used acidic seasoning and can be manufactured using various methods and bases, including cereals, wheat, and fruits. Most studies on vinegar have been conducted to evaluate its antioxidant activity. In the present study, fermented dark vinegar (FDV) produced from unpolished rice was examined for its antimicrobial activity, biochemical content, including the amounts of sugar, total soluble sugar, organic acid, and free amino acids, and pH and physiological activity. The antimicrobial efficiency of FDV was assessed using the paper disc-agar diffusion method. FDV exhibited strong antimicrobial activity against the pathogenic bacteria and yeast strains that were tested. In fact, the activity of FDV was shown to be higher than that of the commercial antibiotics carbenicillin (50 µg/ml) and tetracycline (50 µg/ml) against Staphylococcus aureus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Yersinia enterocolitica, and Lodderomyces elongisporus. The antioxidant activity of FDV and ascorbic acid was evaluated. Using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method, we found that FDV has the highest activity of the antioxidants. After spreading FDV onto tryptic soy broth and yeast extract-peptone-dextrose agar media, the microbial strains were isolated and characterized through physiological and biochemical analysis. Based on 16S ribosomal DNA sequence analysis, the isolated microorganisms exhibited a close similarity to Acetobacter papayae, Acetobacter pasteurianus, and Acetobacter peroxidans.

• The Korean Journal of Food And Nutrition
• /
• v.36 no.4
• /
• pp.244-252
• /
• 2023

This study was conducted to provide basic data on the antioxidant activity, inhibition of adipocyte differentiation and reactive oxygen species (ROS) production of a mixture of Brassica juncea extract (BJE) and fermented black rice fraction (BRF). We investigated the total phenol content, total flavonoid content, antioxidant effects (DPPH radical scavenging, ABTS radical scavenging, reducing power, FRAP and ORAC assay) and anti-obesity activity of the mixture in 3T3-L1 cells. Our results showed that the total phenol and flavonoid content increased with increasing BRF mixture ratio. The antioxidant activity increased as the BRF mixture ratio increased. In addition, BJE and BRF mixtures did not show any cytotoxicity during the 3T3-L1 differentiation period. During adipocyte differentiation, BJE and BRF mixtures significantly inhibited lipid accumulation and ROS production compared to the control group. These results warrant further experiments to develop an anti-obesity functional food using a mixture of BJE and BRF.

• Korean Journal of Food Science and Technology
• /
• v.48 no.4
• /
• pp.361-365
• /
• 2016

This study was conducted to isolate and identify a microorganism that increases tricin-O-(threo-${\beta}$-guaiacylglyceryl) ether (TTGE) content in the hulls of rice (Oryza sativa L.). Bacteria from germinated rice were isolated by enrichment cultivation using yeast mold, luria bertani, potato dextrose and mannitol egg york polymyxin broths. The highest increase in TTGE content ($339.30{\mu}g/g$) was achieved by a microorganism isolated by PDA enrichment cultivation. On the basis of 16S RNA sequence homology and phylogenetic analysis, the isolated bacterium was identified to have 100% similarity with Burkholderia vietnamiensis. The isolated bacteria were short rods, negative for the Gram stain, and positive for the catalase test. The highest TTGE level was $435.86{\mu}g/g$ in 72-h fermented samples, representing a 2.5x increase compared with the control ($175.65{\mu}g/g$). In conclusion, the bacterium isolated from germinated rice extract was Burkholderia vietnamiensis, and the optimum fermentation period to maximize TTGE levels was 72 h. These findings might help in developing functional materials using rice hulls, a waste product of rice milling.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.2
• /
• pp.281-286
• /
• 2014

This study was carried out to develop Yakju, a new kind of Korean traditional rice wine added with bamboo ethanol extract and characterized by containing various health benefits. The wine with bamboo ethanol extract was fermented by adding ginger and pear to improve flavor and quality. Several quality characteristics and physiological functionalities of Yakju were investigated. When bamboo ethanol extract was added to Yakju, the pH level decreased compared to that of the control. However, total acidity and soluble solid levels were higher than those of the control. The alcohol content of Yakju added with bamboo ethanol extract was slightly higher than that of the control. In examining the colors of Yakju containing bamboo ethanol extract, L value was lower than that of the control, whereas b value and brownness were higher. Various organic acids such as citric acid, malic acid, succinic acid, lactic acid, and acetic acid were determined, and the main organic acid among them was lactic acid. Various free sugars such as sorbitol, glucose, and fructose were detected and glucose was the most abundant. Total polyphenol content of Yakju added with bamboo ethanol extract was lower than that of the control. Further, electron-donating ability ranged from 23.8~40.0%, which was higher than that of the control. Nitrite scavenging ability of Yakju added with bamboo ethanol extract ranged from 15.2~36.4%, which was higher than that of the control at pH 6.0. Sensory evaluation of Yakju showed that bamboo ethanol extract+ginger as well as bamboo ethanol extract+ginger+pear treatment significantly increased flavor, taste, and overall acceptance compared to the others.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.12
• /
• pp.1312-1321
• /
• 2011

Enzyme extracts of cellulase [filter paper cellulase (FPase) and carboxymethyl cellulase (CMCase)], chitinase, and chitosanase produced by Aspergillus niger NRRL-567 were evaluated. The interactive effects of initial moisture and different inducers for FP cellulase and CMCase production were optimized using response surface methodology. Higher enzyme activities [FPase $79.24{\pm}4.22$ IU/gram fermented substrate (gfs) and CMCase $124.04{\pm}7.78$ IU/gfs] were achieved after 48 h fermentation in solid-state medium containing apple pomace supplemented with rice husk [1% (w/w)] under optimized conditions [pH 4.5, moisture 55% (v/w), and inducers veratryl alcohol (2 mM/kg), copper sulfate (1.5 mM/kg), and lactose 2% (w/w)] (p<0.05). Koji fermentation in trays was carried out and higher enzyme activities (FPase $96.67{\pm}4.18$ IU/gfs and CMCase $146.50{\pm}11.92$ IU/gfs) were achieved. The nonspecific chitinase and chitosanase activities of cellulase enzyme extract were analyzed using chitin and chitosan substrates with different physicochemical characteristics, such as degree of deacetylation, molecular weight, and viscosity. Higher chitinase and chitosanase activities of $70.28{\pm}3.34$ IU/gfs and $60.18{\pm}3.82$ to $64.20{\pm}4.12$ IU/gfs, respectively, were achieved. Moreover, the enzyme was stable and retained 92-94% activity even after one month. Cellulase enzyme extract obtained from A. niger with chitinolytic and chitosanolytic activities could be potentially used for making low-molecular-weight chitin and chitosan oligomers, having promising applications in biomedicine, pharmaceuticals, food, and agricultural industries, and in biocontrol formulations.

• Asian-Australasian Journal of Animal Sciences
• /
• v.23 no.12
• /
• pp.1578-1586
• /
• 2010

This study estimated the effect of fermented persimmon (Diospros kaki L.) extract (FPE) supplement on feed intake, digestibility, nitrogen (N) balance, and rumen fermentation characteristics in sheep. Five male sheep (Corriedale${\times}$Polwarth) with average body weight of $48.6{\pm}1.3\;kg$ were housed in metabolism crates and assigned to a 5${\times}$5 Latin square design with five consecutive 20-d periods which consisted of 14-d adaptation and 6-d data collection. The sheep were fed ad libitum a diet containing concentrate and rice straw (3:7). The five treatments were FPE supplemented at 0 (Control), 5, 10, 20, and 30 g/kg of concentrate. Intakes of dry matter (DM, p<0.01), organic matter (OM, p<0.01), neutral detergent fiber (NDF, p<0.05), acid detergent fiber (ADF, p<0.05), and nitrogen-free extract (NFE, p<0.01) increased quadratically with increasing intake of FPE supplement and maximized (p<0.05) at 10 g/kg FPE. The digestibilities of DM (p<0.05), OM (p<0.05), crude protein (p<0.01), and NFE (p<0.01) increased quadratically with increasing amount of FPE supplement, and sheep fed 5 and 10 g/kg diets had greater (p<0.05) DM, OM, and NFE digestibilites than the Control treatment. By increasing FPE supplement concentration, N intake (p<0.01) and fecal N (p<0.05) increased linearly, whereas retained N (p<0.05) and retained N ratio (p<0.05) increased quadratically. The retained N was maximized (p<0.05) in sheep fed 5 and 10 g/kg diets. The mean rumen pH was not affected by FPE supplement, but there was a quadratic increase (p<0.05) of mean rumen ammonia N concentration and a linear increase (p<0.01) in mean rumen total volatile fatty acid (VFA) and acetate concentrations. The mean concentration of rumen propionate in sheep fed all FPE supplemented diets was greater (p<0.05) than the Control, but the mean ratios of rumen acetate to propionate in sheep fed 5 and 10 g/kg diets were lower (p<0.05) than that of Control sheep. In conclusion, FPE supplemented at 5-10 g/kg of concentrate improved feed intake, the digestibilites of OM and NFE, N metabolism, and rumen fermentation indices of sheep.

• Journal of Life Science
• /
• v.31 no.2
• /
• pp.192-198
• /
• 2021

Red yeast rice has been extensively used as food and traditional medicine for thousands of years in East Asian countries. It is produced by the fermentation of a particular yeast (in general, Monascus purpureus) as rice and various cereals (barley, soybean, etc.). Monascus sp. produces many secondary metabolites during its growth, including pigments, monacolins, and γ-aminobutyric acid. Some metabolites―specifically, monacolin K, γ-aminobutyric acid, dimerumic acid, and monascus pigments―have been reported to lower cholesterol and blood pressure while showing anti-obesity effects. In this study, we investigated the anti-obesity effect of ethanol extract from red yeast barley (RYB) fermented with Monascus sp. BHN-MK 2 on 3T3-L1 cells. The anti-obesity effects of RYB extract were examined: its lipid accumulation inhibitory effect was tested by Oil Red O staining, and obesity-related mRNA expression levels were tested by real-time RT-PCR in MDI stimulated 3T3-L1 cells. The intracellular lipid content of MDI-stimulated 3T3-L1 cells decreased significantly to 5.04%, 12.24%, and 23.52% in response to 200, 400, and 800 ㎍/ml RYB, respectively. Moreovers, we evaluated that RYB extract significantly downregulated the expression of C/EBPα, SREBP-1, and PPAR-γ gene in a dose-dependent manner. As a result, red yeast barley ethanol extracts exerted the strongest anti-obesity effects. Also, the results indicate that red yeast barley could be used as a functional anti-obesity food material.

• Journal of Nutrition and Health
• /
• v.38 no.7
• /
• pp.586-604
• /
• 2005

A reliable nutrient database is a prerequisite for accurate calculation of dietary intakes. The folate database currently available in Korea, however, is not reliable because the values were obtained from published data in other countries using ineffective methods to extract folates from the food matrix. The purpose of this study was to complement the folate database by analyzing folate content in foods using a more effective method to extract food folates (trienzyme treatment). Folate content per unit weight was highest in laver, fermented soybeans, soybean, spinach, black soybeans, crown daisy, mung beans, and quail's egg in descending order. Legumes, leafy greens, eggs, and seaweeds were rich in folate, and meats, chicken, fish, and some fruits contained less folate. Some of the analyzed values were 10 times higher than those in the currently available database. Folate values of 423 foodcodes out of 2,932 foodcodes ($14.4\%$) in the database in the 7th revision in the Recommended Dietary Allowances for Koreans can be replaced by those analyzed in this study. Since folate values of rice and Kimchi, which are core dishes of Koreans, in the newly established database are higher than those in the current database, folate intake assessed using our data will be higher than that using the current available database. Folate content in more foods commonly consumed in Korea are needed to update the folate database. Meanwhile, folate values presented here can be used to assess dietary folate intake of the Korean population.

• Korean Journal of Food Science and Technology
• /
• v.29 no.3
• /
• pp.581-587
• /
• 1997

For bifidus fermentation food, gelatinized rice solution was fermented without liquefaction/saccharification by amylolytic Bifidobacterium spp. isolated from Korean. Eighteen amylolytic Bifidobcterium on the starch agar were isolated from 38 Korean and four strains were finally selected as good amylase producers. The most enzyme-producing strain of Bif. sp. FBD-12 secreted extracellular amylase of 0.17 U/mg and intracelluar amylase of 1.8 U/mg. Three strains of Bif. sp. FBD-12, Bif. sp. FBD-16 and Bif. sp. FBD-17 also showed good growth on pH controlled media by HCI/acetic acid to pH 5.0 while Bif. sp. FBD-6 was not so tolerant that viable cell counts reduced to $10^2\;CFU/mL$ times on the media. Initial cell number of $10^6\;CFU/mL$ for those strains reached to $10^9\;CFU/mL$ on the rice medium supplemented with yeast extract (0.2%) and cysteine (0.05%). Ascorbic acid instead of cysteine was added to the medium for improving off-flavour and the best growth was shown at 0.1% addition. Isolated soybean proteins (ISP) of 3% accelerated the growth of the strains. Maximum count of $10^9\;CFU/mL$ reached within 12 hour fermentation on the rice medium with ascorbic acid and isolated soybean protein instead of 32 hours on the cysteine medium, and total acidity increased from 0.5% to 1% on each media. Reducing sugar in the ascorbic acid/ISP cultures generally increased especially 2 mg/mL to 15.5 mg/mL for Bif. sp. FBD-6. From sensory evaluation, the products showed good acceptability so that it suggested possibility of development of bifidus-fermented rice food.