Seok-Tae Jeong

Preparation and Characterization of Urushiol Free Fermented Rhus verniciflua Stem Bark (FRVSB) Extracts

The water extract of the fermented Rhus verniciflua stem bark (FRVSB) was prepared by hot water extracting at 100 o C for 8 h. The urushiol content of the FRVSB water extract was determined by HPLC. The urushiol was not contained in FRVSB water extract, whereas Rhus verniciflua stem bark (RVSB) water extract contained 3.4 mg%. At the lab scale size, suitable water extraction condition for a total solid, polyphenol and flavonoid from FRVSB was at over 100 o C for 6-8 h. The total solid contents was reduced in pilot scale processing system, with 5.7% of the extraction yield. The proximate composition (%) of FRVSB water extract obtained from industrial installation was moisture 4.34, crude fat 1.69, crude protein 10.21, and crude ash 15.80. Gallic acid (1,090.5 mg%) was the most abundant compound in phenolic acids, while fisetin (135.7 mg%) was the predominant flavonoid. The free sugar content was mannitol of 3.48%, glycerol of 0.19%, and glucose of 0.19%. Alanine (244 ppm), serine (231 ppm), and leucine (218 ppm) were predominant amino acids.

Quality Characteristics and Biogenic Amine Production of Makgeolli Brewed with Commercial Nuruks

Makgeolli mashes that were brewed using five different commercial nuruks (fermentation starters) were investigated for changes in physicochemistry, microbial diversity, and biogenic amine (BA) production. Mash A brewed with the nuruk (Gaeryang-nuruk) had the highest level of alcohol concentration and the greatest number of yeast cells, whereas mash E had the greatest number of bacterial cells. Only three biogenic amines were detected in the makgeolli mashes: tyramine, putrescine, and cadaverine. Using a PCR-DGGE technique, we observed that mash E had the highest BA production, and had the greatest number of bands on the denaturing gradient gels. We also observed that the numbers of bacterial cells correlated significantly with the putrescine and the total BA content, and that the BA content correlated significantly with the color values (L, a, b). This study shows that the quality of a makgeolli can depend on the type of nuruk. Therefore, we suggest that the quality management of makgeolli should start with the stage of nuruk manufacture.

Changes in Physiochemical Properties of Yakju Prepared by Accelerated Aging without Protease

C in yakju (traditional Korean rice wine) prepared withoutthe addition of protease (non-addition group). The total concentration of organic acids increased by 1.0-2.7 fold in the non-addition group. While the concentration of lactic acid and acetic acid increased, the pyroglutamic acid concentrationdecreased by 51.1 fold. Consequently, the total acidity and volatile acid concentration increased, and the overall pHdecreased. Compared to the addition group, the non-addition group showed a 3.0-5.2 fold increase in the amount of aminoacids; however, the total estimated concentrations of free-form amino acids were 5.2-11.9 times lower than those in thelatter group. The major amino acids found in the non-addition group were alanine, arginine, leucine, and phenylalanine.The yakju preparation from the non-addition group showed a 1.2-3.0 fold decrease in the final color intensity as comparedto that from the addition group.Keywords: yakju, aging, protease, free amino acid, Korean rice wine

Physicochemical Properties and Physiological Activities of Rhus verniciflua Stem Bark Cultured with Fomitella fraxinea

The contents of proximate composition, free amino acids and phenolic acids in the Fomitella fraxinea cultivated-Rhus verniciflua stem bark(FRVSB), and its adipogenesis effect were investigated. The proximate composition(%) of FRVSB was as follows: moisture(7.64), ash(6.30), crude fat(3.86), crude protein(3.59) and sugar(not detected); while Rhus verniciflua stem bark(RVSB) contained 1.64, 8.09, 7.28, 6.48 and 5.39, respectively. The total free amino acids concentration was 97.41 mg% in FRVSB and 71.91 mg% in RVSB. Phosphoserine(55.06 mg%), ammonia(17.84mg%) and aspartic acid(6.05mg%) were predominant amino acids. The content of total phenolic acids was 422.89 ppm in ethanol extract and 283.86 ppm in water extract, with syringic and gallic acid as the main component. The FRVSB extracts showed a potent free radical scavenging activity for DPPH(2,2-diphenyl-1-picrylhydrazyl hydrate) with of (EtOH) and (water), respectively, whereas value of gallic acid was . The protective effect of both ethanol and water extract the extracts against UV-induced oxidative stress in NIH3T3 was observed. The water extracts of FRVSB may promote adipogenesis in 3T3-L1 cells.

Effect of the Extracts from Fermented-Rhus verniciflua Stem Bark with Fomitella fraxinea on the Growth and Enzyme Activity of Soybean Product-fermenting Microorganisms

Department of Food Science and Technology, Chonbuk National University, Iksan 570-752, Korea(Received 30, October 2012., Revised 8, December 2012., Accepted 19, December 2012)ABSTRACT: We studied the effect of fermented Rhus verniciflua stem bark (FRVSB) extract (used in herbal med-icine by Koreans) on the microbial growth and enzyme activity of 12 soybean-fermenting microorganisms, includingBacillus spp., lactic acid bacteria, yeast, and other harmful bacteria. The ethanol and methanol extracts of FRVSBinhibited the growth of Bacillus subtilis, Bacillus licheniformis, Bacillus cereus, and Zygosaccharomyces rouxii, andin the disk diffusion assay, their inhibition zone diameters were 11.06-12.23, 12.32-18.38, 11.47-11.84, and 13.59-14.21mm, respectively. The water extract did not show any inhibitory effect. In fact, the water extract addition enhancedthe growth of B. subtilis and B. licheniformis by 1.3-4.5 fold and that of B. cereus by 1.2-1.4 fold. However, thewater extract did not affect the growth of Lactobacillus plantarum, Lactobacillus mesenteroides, Saccharomyces cer-evisiae, and Escherichia coli. The addition of water extract increased the amylase and protease activity of B. subtilisand B. licheniformis.KEYWORDS : Fomitella fraxinea, FRVSB, Rhus verniciflua, Soybean product

Changes Observed in Doenjang (Soybean Paste) Containing Fermented-Rhus verniciflua Extract During Aging

Fermented-Rhus verniciflua (FRV) extract is increasingly used in fermented soy products, fermented vinegars, and certain alcoholic beverages. In this study, we investigated the effects of FRV extract on the physicochemical properties of doenjang (soybean paste). Addition of FRV extract to doenjang resulted in a 28.2-45.4% increase in the amino acid content and a 1.3- to 1.5-fold increase in the concentrations of glutamic acid, which imparts a savory flavor to doenjang. The concentration of biogenic amine (BA) of the sample containing the extract was 5.3-52.6% lower than that of the control. The major components of BA included tyramine (55.1-74.6%), followed by putrescine, spermidine, tryptamine, and cadaverine, in decreasing concentrations. The organic acid concentration of the sample containing the extract was 1.2-1.3- fold higher than that of the control. The total free sugar concentration was 163.4 mg/100 g in the control and 206.6-276.8 mg/100 g in the supplemented sample, showing a 1.3- to 1.9-fold increase as the addition of the extract.

Effect of Urushiol-Free Extracts from Fermented-Rhus verniciflua Stem Bark with Fomitella fraxinea on the Fermentation Characteristics of Doenjang (Soybean Paste)

된장제조공정에 발효옻 추출물을 첨가하고 염수발효기간 동안의 미생물, 효소활성, 유리아미노산, 유기산 및 일반성분 변화를 조사하였다. 염수발효 42일 경과 후 추출물 첨가군(0.7%, 2.0%, 5.0%, 10.0%, w/v)의 염수 중 총 유리아미노산 함량은 2188.3, 4634.7, 2982.7, 5070.6 mg/100 mL로 대조군 보다 각각 1.3, 2.8, 1.8, 3.1배 높게 나타났다. 염수를 걸러낸 된장의 미생물 분포는 일반세균

Characterization of Yeast for Soju (Distilled Spirits) from Korean Traditional Nuruk

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Effect of Organic Acids Addition to Fermentation on the Brewing Characteristics of Soju Distilled from Rice

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Comparison of the Flavonoid and Urushiol Content in Different Parts of Rhus verniciflua Stokes Grown in Wonju and Okcheon

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