The Change of Characteristics and Antioxidant Activity of Cocoa Vinegar During Fermentation of Pulp Liquids by Adding Tape Yeast

摘要

The pulp liquids as a by-product of cocoa beans fermentation is potential to be used as a raw material for making cocoa vinegar, but unfortunately the content of acetic acid is relatively low and there have been no studies related to antioxidant activities. The objectives of the present study were to examine the effect of addition of tape yeast and fermentation time of pulp liquids to the changes of characteristics and antioxidant activities of cocoa vinegar and to define the best treatments of the addition of tape yeast and fermentation time for making cacao vinegar. The experiment in this study used factorial Group Randomized Design (GRD) with 2 factors. Factor I is the addition of tape yeast consisting of 5 levels, namely: without tape yeast (control), addition of 0.05; 0.10; 0.15 and 0.20% (w/v) and factor II is fermentation time which consists of 6 levels, namely: 5, 10, 15, 20, 25 and 30 days. The characteristics of cacao vinegar observed were as stated in SNI 01-437-1996, including: acetic acid, acidity (pH), total soluble solid (TSS), total sugar, and alcohol; and the antioxidant activity, namely: total phenolic and antioxidant capacity. The results showed that: (1) the changes in the characteristics of cocoa vinegar consisting of acetic acid content, acidity (pH), total soluble solids (TSS), total sugar content, and alcohol content; and the antioxidant activity based on the total phenolic content and antioxidant capacity occurred during fermentation with the addition of tape yeast, (2) the best treatment for making cocoa vinegar is the addition of 0.10% tape yeast and 25 days fermentation time, with its characteristics namely: 4.09±0.01% acetic acid content, acidity (pH) of 3.40±0.00, TSS of 5.05±0.07 (°Brix), 0.49±0.02% total sugar content, and 0.00% alcohol content; and antioxidant activities, namely: total phenolic content of 78.94±6.54 (mg/100g GAE) and antioxidant capacity of 12.50±0.14 (mg/L GAEAC).