Evaluation of Physicochemical Properties of South African Cashew Apple Juice as a Biofuel Feedstock

Abstract

Cashew apple juice (CAJ) is one of the feedstocks used for biofuel production and ethanol yield depends on the physical and chemical properties of the extracted juice. As far as can be ascertained, information on physical and chemical properties of South African cashew apple juice is limited in open literature. Therefore, this study provides information on the physical and chemical properties of the South African cashew apple juice. Physicochemical characteristics of the juice, such as specific gravity, pH, sugars, condensed tannins, Vitamin C, minerals, and total protein, were measured from a mixed variety of cashew apples. Analytical results showed the CAJ possesses specific gravity and pH of 1.050 and 4.52, respectively. The highest sugars were glucose (40.56 gL −1 ) and fructose (57.06 gL −1 ). Other chemical compositions of the juice were condensed tannin (55.34 mgL −1 ), Vitamin C (112 mg/100 mL), and total protein (1.78 gL −1 ). The minerals content was as follows: zinc (1.39 ppm), copper (2.18 ppm), magnesium (4.32 ppm), iron (1.32 ppm), sodium (5.44 ppm), and manganese (1.24 ppm). With these findings, South African CAJ is a suitable biomass feedstock for ethanol production.