Production of Wine and Vinegar from Cashew (Anacardium occidentale) “Apple”

Abstract

Aims: To prepare commercial-grade wine from cashew apples using less expensive household materials and vinegar production by natural spontaneous fermentation. Study Design: Cashew wine was prepared by fermenting cashew apple juice with Saccharomyces cerevisae. Various parameters viz., time, pH, temperature, density and vinegar concentration was monitored. Place and Duration of Study: Biochemistry Division and New Product Development Unit, Cocoa Research Institute of Ghana, between February 2009 and July 2013. Methodology: Progress and quality of fermentation were carried out by using various biochemical tests. Acceptability of products was determined by sensory analysis. Results: Physico-chemical analyses of the wine during fermentation showed a decrease in specific gravity and pH, and a corresponding increase in titratable, fixed and volatile acidity. The ageing wine was amber, dry (12.58±0.24%v/v alcohol content), slightly acidic in taste (titratable acidity of 0.79±0.02 g tartaric acid/100 mL and pH of 3.84±0.04) and had high phenolic content (406.10±4.56 mg/100 mL) and a distinct cashew apple juice smell. Microbiological assay of the wine showed no microbial growth. Sensory evaluation showed no significant differences (P>.05) between the cashew wine and a commercial grape wine with respect to clarity, colour, taste, astringency and aftertaste. However, in terms of aroma, the grape wine was found to be significantly superior (P<.05) to the cashew wine. Vinegar was produced by natural spontaneous acetic acid fermentation of the cashew wine. Chemical monitoring of the acetic acid fermentation showed a decline in both alcohol and pH from 7.14±0.04%v/v to 0.00±0.04%v/v and 4.23±0.03 to 2.40±0.27 respectively over a period of 29 days. Conversely, volatile acidity increased from 0.01±0.01 g acetic acid/100 mL to 6.85±0.03 g acetic acid/100 mL over the same period. The characteristics of the cashew vinegar met the standard specifications for vinegar. Conclusion: This study shows that ordinary household materials could be used to commercially exploit the underutilised cashew apples in Ghana through the production of wine and vinegar to conserve foreign exchange and increase the income of farmers in the country.