• The Korean Journal of Mycology
• /
• v.41 no.3
• /
• pp.167-171
• /
• 2013

The goal of this study was to screen a useful alcohol fermentative yeast for Gugija leaf makgeolli (Gl makgeolli) brewing and establish its optimal fermentation condition. Gugija leaves with various alcohol fermentative yeasts were added into the mixture of cooked non-glutinous rice and koji, and then fermented at $25^{\circ}C$ for 7 days. Among several Gl makgeolli, ethanol contents was the highest in Gl makgeolli made by S. cerevisiae F-1. Therefore, we selected S. cerevisiae F-1 as suitable yeast for brewing of Gl makgeolli. Gl makgelli with the best total acceptability and high antihypertensive action was obtained when cooked non-glutinous rice (120 g), boiled D.W (100 mL) and JJ koji (60.5 g/300 sp) were mixed and fermented for 2 days at $30^{\circ}C$ with S. cerevisiae F-1 (5%), and added again cooked non-glutinous rice (150 g), glutinous rice (100 g), D.W (500 mL) and Gugija leave (0.1%/cooked rice) and further fermented for 5 days at $25^{\circ}C$.

• Food Science and Preservation
• /
• v.23 no.1
• /
• pp.117-126
• /
• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• Microbiology and Biotechnology Letters
• /
• v.25 no.2
• /
• pp.203-206
• /
• 1997

Takju is a traditional alcoholic beverage that has been prepared by fermenting the cooked rice and Nuruk (Korean-style bran koji). During fermentation. bacterial contamination is a problem which inhibits the growth of yeast and thus lowers the ethanol production from starch of rice, and causes souring. Major contaminants were known to be gram-positive acid producers at the early stage of fermentation. This problem would be solved if the contaminated bacteria could be controlled. Nisin, a GRAS-grade preservative, was added at the level of 500 iu/g as it retards the growth of the gram-positive bacteria. It was possible to control acid and ethanol production during fermentation. This process increased the ethanol production by 2 % comparing with control.

• Microbiology and Biotechnology Letters
• /
• v.9 no.2
• /
• pp.65-69
• /
• 1981

As a process to utilize agricultural residues, simultaneous hydrolysis-fermentation (SSF) was compared with fermentation of enzymic hydrolyzate using koji cultures of Trichoderma sp. KI 7-2 and a thermotolerant yeast Saccharomyces cerevisiae NCYC 716. Cellobiose was not detected in SSF broth whilst 15 mg/$m\ell$ of the disaccharide was found in enzymic hydrolysate of rice straw using the same enzyme source. It was found that converting glucose to ethanol in SSF process reactivated the cellobiase activity, which is inhibited by the accumulation of glucose in enzymic hydrolysis process. Cutting milled rice straw was fermented as effectively as ball milled one in SSF process. From tile results discussions are made on the product inhibition mechanism of cllulolytic enzyme system.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.42 no.9
• /
• pp.1461-1466
• /
• 2013

In this study, we ascertained the characteristics of crude protease extracted from fruits (fig, kiwifruit and pineapple) as well as traditional Korean fermentation starters (bio nuruk, traditional nuruk, meju and rice koji) to determine their suitability for industrial application. Crude protease extracted from traditional Korean fermentation starters was found to have a higher optimum temperature ($70^{\circ}C$) and salt concentration (1~3%) but a lower optimum pH (3~6) value compared to the corresponding values for the protease extracted from fruits. On comparison, the total activities of protease per gram unit follow the order: bio nuruk> rice koji> traditional nuruk> fig> pineapple> meju> kiwifruit. Based on our results, we conclude that protease extracted from traditional Korean fermentation starters has potential for application in food industry, for example, as a meat tenderizer for sausage manufacturing and as a protease for cheese production.

• Food Science and Preservation
• /
• v.20 no.6
• /
• pp.805-809
• /
• 2013

This study was carried out to investigate the effects and characteristics of sausages with red yeast rice added, particularly the Monascus purpureus KFRI 1134 strains, and to decide the optimal quantity of red yeast rice used. The additional rate of red yeast rice which has been used as a material for reducing nitrite, a coupler in meat products were 0, 1, 3, and 5% (w/w). In terms of the effects of the red yeast rice on the color, texture properties, and sensory characteristics of the sausages, the optimal temperature at which color stability was shown was below $100^{\circ}C$, and the addition of 1% red yeast rice resulted in a distinctly attractive color and increasingly improved the red color in the UV-visual Spectrophotometer analysis. However, the addition of over 1% (w/w) resulted in an unattractive color. The red colors also had strong heat stability. The texture properties and taste of the sausages were not affected by the red yeast rice.

• Journal of Microbiology and Biotechnology
• /
• v.22 no.12
• /
• pp.1749-1757
• /
• 2012

Makgeolli is a traditional rice wine favored by the general public in Korea. This study investigated the fermentation and sensory characteristics of using wild yeast strains for brewing makgeolli. A non-Saccharomyces cerevisiae strain was isolated from nuruk and termed Y197-13. It showed 98% similarity to Pichia anomala and had an optimal growth temperature of $25^{\circ}C$. Makgeolli was manufactured using koji, jinju nuruk, and improved nuruk as fermentation agents. Y197-13 makgeolli brewed with koji had alcohol and solids contents of 11.1% and 13.9%, respectively. Sweet sensory characteristics were attributed to residual sugars in makgeolli with 6% alcohol. The makgeolli had a fresh sour taste and carbonated taste. Volatile component analysis showed the isoamyl alcohol, phenylethyl alcohol, isoamyl acetate, and fatty acid, including ethyl oleate and ethyl linoleate, relative peak area was higher in Y197-13 makgeolli than in makgeolli with Saccharomyces cerevisiae. These results suggest the wild yeast, Y197-13, as a candidate for brewing makgeolli.

• Food Science and Preservation
• /
• v.30 no.4
• /
• pp.669-682
• /
• 2023

The production of distilled soju by fermenting nonsteamed rice was evaluated using commercial enzyme products. White koji and modified nuruk had alpha-amylase activities of 31.90 U/g and 3,532.71 U/g, respectively, and gluco-amylase activities of 698.32 U/g and 4,899.58 U/g, respectively. The enzyme products had activities of 5,604.15-225,182.00 U/g and 13,517.41-120,822.41 U/g, respectively. At enzyme concentrations of >800 mg/L, the Chung-moo-purified enzyme had an alcohol productivity of ≥19%. Nurukzyme R400, Sanferm Yied, and Diazyme X4 exhibited alcohol productivities of >19% at concentrations of >600 mg/L. The alcohol content of the vacuum distillates was 41.31%-44.86%. The volatile component with the alcohol content adjusted to 25% was analyzed and principal component analysis was performed. The volatile components in white koji, Diazyme X4, and Sanferm Yield were similar. The modified nuruk treatment group had a relatively high ethyl lactate content compared to the white koji treatment group. The Nurukzyme R400 treatment group had high contents of butyric acid and ethyl butyrate. The Chung-moo-purified enzyme was characterized by a low component content. Thus, when enzyme products were used in nonsteamed rice fermentation, no effect on the alcohol productivity and quality of vacuum distilled soju was observed, suggesting that it can replace white koji and modified nuruk.

• Microbiology and Biotechnology Letters
• /
• v.7 no.2
• /
• pp.91-95
• /
• 1979

Ethanol and Xylose were produced from cellulosic agricultural waste such as rice straw and corn cob by a single-step simultaneous hydrolysis-fermentation process utilizing semi-solid culture of Trithoderma as enzyme source and Saccharomyces yeast. By this process all the hexoses prduoced by the enzyme were converted to ethanol leaving pentoses which are not fermented by the yeast. By processing 50 g of rice straw, 18 ml of ethanol and 2.7 g of xylose were produced and 50 g corn cob produced 3.8 ml of ethanol and 10.8 g of xylose. Alkali-treatment of rice straw showed little effects on the productivities of ethanol and xylose. The possible reasons are discussed.

• Preventive Nutrition and Food Science
• /
• v.7 no.4
• /
• pp.405-410
• /
• 2002

Rice wine was prepared with medicinal plants or plant extracts to obtain a value added nutritious alcoholic tonics. Powders of ten medicinal plants (PTM) or aqueous extracts prepared from them (ATM) were added during the initial stage of fermentation. Aroma compounds of rice wine (control) and wines containing PTM or ATM were isolated by liquid-liquid continuous solvent extraction (LLCSE) and analyzed by gas chromatography-olfactometry and aroma extract dilution analysis (AEDA). Desirable aroma compounds: acetaldehyde (sweet, ethereal), benzaldehyde (sweet, fragrant), ethyl acetate (sweet) and ethyl octanoate (sweet, ethanolic) had the highest log$_3$-flavor dilution (FD) factors in ATM. Results of sensory evaluation demonstrated that intensities of undesirable aroma attributes, such as koji and yeasty notes in control, and raw medicinal herb notes in PTM, were lowest in wine with ATM. Wines made with ATM had the most attractive aroma attributes among the three different traditional Korean medicinal wines.