• The Korean Journal of Mycology
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• v.38 no.2
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• pp.184-188
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• 2010

The goal of this study was to screen a useful yeast for Korean traditional pear Yakju (KTPY) brewing and develop its brewing process. Cooked non-glutinous rice and nuruk were mixed, and added into pear juice with various Saccharomyces cerevisiae and then fermented at $25^{\circ}C$ for 7 days. Among several alcohol fermentation yeasts, ethanol contents was the highest in pear Yakju made by S. cerevisiae K-7 and also showed high ethanol content in pear Yakju which was made by commercial S. cerevisiae C-2. Therefore, we selected S. cerevisiae K-7 and S. cerevisiae C-2 as suitable yeasts for brewing of KTPY. Maximal ethanol production (10.4%) was obtained when cooked non-glutinous rice (100 g) and nuruk (30 sp/g) were mixed and added into pear juice (600 ml) with S. cerevisiae K-7 (5%) and fermented at $25^{\circ}C$ for 7 days and also its antihypertensive angiotensin I-converting enzyme (ACE) inhibitory activity was 57.2%. Addition of antihypertensive starchy materials into the mash was not affected in ACE inhibitory activity and total acceptability of KTPY.

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