Quality Characteristics of Brown Rice Vinegar by Different Yeasts and Fermentation Condition

Abstract

This study investigated the quality characteristics of brown rice vinegar (agitated culture and static culture) derived from brown rice Takju with different types of yeasts. The alcohol content by yeast was the highest in B (brown rice Takju produced by S. cerevisiae GRJ) at 14.3% and the titratable acidity was less than 0.6% in all ranges. When quality characteristics of agitated and static culture brown rice vinegar using them were compared, acidity of agitated culture vinegar recorded the highest level or 6.05% at 7 day of fermentation DV (brown rice vinegar produced by S. kluyveri DJ97) with the initial acidity of 1.0% and the initial pH of 3.9～4.0, and AV (brown rice vinegar produced by S. cerevisiae JK99), CV (brown rice vinegar produced by S. cerevisiae H9) and BV (brown rice vinegar produced by S. cerevisiae GRJ) recorded as 5.64, 5.55 and 5.32%, respectively. In addition, acidity of static culture vinegar increased continuously to 5.01～5.31% until the 14 day of fermentation and then tended to decrease slightly from the 16 day of fermentation. Difference in acidity and pH of brown rice vinegar according to types of yeast was not significant. Comparison of free amino acid of brown rice vinegar showed that for agitated culture brown rice vinegar, the content of total free amino acid was higher in the order of BV, DV, AV and CV and the content of essential amino acid was the highest in BV by recording over 1,000 ppm. The content of total free amino acid of static culture brown rice vinegar was higher than that of agitated culture vinegar in all ranges and especially static culture brown rice vinegar contained more serine, alanine, valine, isoleucine, leucine and γ-aminobutyric acid than agitated culture vinegar. In particular, γ-aminobutyric acid recorded over ten times higher level or 456.91～522.66 ppm. From these results, quality characteristics of brown rice vinegar was affected by acetic acid fermentation methods rather than types of yeast. However, as future aging process is expected to change flavor components and sensory characteristics, studies on various quality factors of vinegar are needed.

Chemical Characteristics and Flavors of Bamboo-shoot Vinegar

“…식초의 품질은 초산의 함량, 휘발성 향기성분, 미량의 각종 유기산 및 아미노산, 당류, 염류 등의 다양한 요인 에 의해 결정되며(13) 특히 휘발성 향기성분의 경우 산, 에스터, 알데하이드류의 화합물이 유기적으로 작용하여 특유의 향기를 나 타낸다 (10). 국내의 식초 산업은 1970년대 발효과정을 거치지 않 고 빙초산, 물, 향신료 등을 혼합하여 제조하는 합성식초로부터 시작하여 80년대에는 초산을 발효시켜 과즙, 무기염 등을 첨가한 양조식초로 산업화가 진행되었으며 근래에는 단순 조미료가 아 닌 건강 식품으로 100% 과실을 원료로 하는 천연 양조식초로의 산업이 활발히 진행되고 있다 (11,(13)(14)(15). 또한 과실뿐만 아니라 호 박, 마늘, 무 등의 채소 및 인삼, 홍삼, 삼백초, 솔잎 등의 초목 을 원료로 한 천연 양조식초의 개발이 활발히 연구되고 있다 (16,17).…”