Optimization of the Acetic Acid Fermentation Condition of Apple Juice

Abstract

This study was conducted to determine the acetic-acid fermentation properties of apple juice (initial alcohol content, apple juice concentration, acetic-acid content, and inoculum size) in flask scale. At the acetic-acid fermentation of apple juice with 3, 5, 7, and 9% initial alcohol content, the maximum acidity after 10-day fermentation was 5.88% when the initial alcohol content was 5%. The acetic-acid fermentation did not proceed normally when the initial alcohol content was 9%. When the initial Brix was 1°, the acidity gradually increased, and the acidity after 12-day acetic-acid fermentation was 4.48%. Above 4% acidity was attained faster when the apple juice concentration was 5 and 10 ˚Brix than when it was 1 and 14 ˚Brix. When the initial acidity was 1% or above (0.3, 0.5, 1.0, and 2.0%), the acetic-acid fermentation proceeded normally. The acetic-acid fermentation also proceeded normally when the inoculum sizes were 10 and 15%, and the acidity after eight-day acetic-acid fermentation was 5.60 and 6.05%, respectively. Therefore, the following were considered the optimal acetic-acid fermentation conditions for apple cider vinegar: 5% initial alcohol content, 5 ˚Brix or above apple juice concentration, 1.0% or above initial acidity, and 10% or above inoculum size. Apple cider vinegar with above 5% acidity can be produced within 48 h under the following acetic-acid fermentation conditions: 7% initial alcohol content, about 1% initial acidity, and 10% inoculum volume at 30℃, 30 rpm, and 1.0 vvm, using 14 ˚Brix apple juice in a mini-jar fermentor as a pre-step for industrial-scale adaptation.

Enhanced antioxidant capacity of brown rice vinegar supplemented with soy residue

“…For acetic acid fermentation, the alcohol contents of BRV and BROV3 were adjusted to 5.5%, which is suitable for the growth of acetic acid bacteria. Acetic acid bacteria do not proceed with normal acetic acid fermentation if the alcohol content is lower or higher than the appropriate concentration (4%–8%) (Kang et al, 2011). The alcohol content of BROV5 did not require any adjustments.…”

Fermentation characteristics of cider from late harvest Fuji apples by a sugar tolerant yeast, Saccharomyces cerevisiae SS89

“…사과는 주로 생과 형태로 유통되고 있지 만 가공 적성이 비교적 우수하여 사과주, 주스, 잼 등 다양한 식품으로 가공되기도 한다 (4). 현재 국내에서 사과를 가공 용 원료로 활용하기 위한 연구로는 사과주스의 가공(5,6)이 나 사과를 이용한 발효주 (7)(8)(9), 사과 식초의 제조 및 발효 (10,11), 동결농축에 의한 무가당 아이스 사과주 발효(9)에 관한 연구 등이 보고된 바 있다. 사과를 파쇄하여 과즙을 제조한 후 발효하여 제조하는 사과주는 영국과 독일을 중심으로 주로 발전하여 왔으며 아직 그 과정이 잘 알려지지 않은 발효과정 중에 생성되는 휘발성 생성물들의 화학적 구성에 의해 일반적으로 포도주 보다 변질이 적은 것으로 알려져 있다 (12).…”