Ji-Eun Kang

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

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

0.3-12.0{\times}10^8

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

, 곰팡이

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

3.0-21.0{\times}10^4

The Quality Characteristics of Commercial Deonjang Certified for Traditional Foods

, 효모

Effect of cell wall degrading enzyme and skin contact time on the brewing characteristics of Cheongsoo grape

1.0-2.0{\times}10^4

Physicochemical Properties of Korean Non-sterilized Commercial Makgeolli

, 대장균 불검출, B. cereus