Journal of Engineering Science and Technology (Jun 2014)
COCONUT WATER VINEGAR: NEW ALTERNATIVE WITH IMPROVED PROCESSING TECHNIQUE
Abstract
Vinegar is a condiment made from various sugary and starchy materials by alcoholic and subsequent acetic fermentation. Vinegar can be produced via different methods and from various types of raw material. A new alternative substrate for vinegar production namely mature coconut water has been tested and was compared with 2 common substrates which were coconut sap and pineapple juice. Substrates such as sap and juices have been found to have high amount of total soluble solids which corresponding to high sugar content in the substrates which is more than 14oBrix. Therefore, both substrates could be directly used for vinegar production without requirement of other carbon sources. However, coconut water which showed low Brix value need to be adjusted to 14oBrix by adding sucrose prior to the fermentation process. Substrates fermented with Saccharomyces cerevisiae have yielded 7-8% of alcohol within 7-10 days aerobic incubation at room temperature. The alcoholic medium were then used as a seed broth for acetic fermentation with Acetobactor aceti as inoculums and fermented for approximately 2 months to obtain at least 4% of acetic acid. Investigation on the effect of inoculum sizes and implementation of back-slopping technique were performed to improve the processing method for coconut water vinegar production. The results show that 10% of inoculum size was the best for acetic acid fermentation and the back-slopping technique has helped to reduce the process time of coconut water vinegar production.