Research Article
Byaruagaba-Bazirake GW, Van Ra
Abstract
Enzyme treated banana juices of three cultivars from tropical and subtropical Africa were studied. The main aim in this study was to apply commercial enzymes to banana pulp and improve on juice extraction and clarification. The banana cultivars which were selected for this study were Kayinja (ABB genotype), Mbidde (AAA-EA genotype), and Bogoya (AAA genotype). Two types of banana belonging to the same genotype (Musa, AAA) grown in the tropical and sub-tropical regions of Africa, known as Williams and Gros Michel in South Africa and Uganda respectively were used for comparison of physicochemical properties. All the cultivars were purchased at full maturity and ripened to stage 8 (yellow, speckled brown) of ripeness under similar warm conditions. Different commercial enzyme preparations were added to banana pulps in the preliminary experiments at the rate of 0.03 g/L for pectin de-pectinisation and de-esterification at 15°C for 24 hours. After juice extraction four pectinolytic enzymes (Rapidase X-Press, Rapidase CB, Rapidase TF and OE-Lallzyme) were selected for further experiments. The parameters that were analysed for comparison included juice yield, total soluble solids, total acidity, pH, viscosity, specific gravity and turbidity. The juice yield was significantly improved (477% v/w) in one of the enzyme treated samples compared to the control in the Kayinja (ABB genotype). The soluble solids in the juice of the three cultivars ranged between 15o and 27oBrix. The total soluble solids of bananas of the same genotype but grown in different climates differed significantly (p<0.05). Turbidity was lower in all the enzyme-treated juices samples compared to the control samples in the 3 cultivars. The overall acceptability of the juices was assessed by a panel and scored more than six points on the nine-point hedonic scale that is at least 66.7% of the juice is acceptability in general.