Yield, characteristics and composition of banana juice extracted by the enzymatic and mechanical methods

Abstract

A comparative study of the enzymatic and mechanical banana juice extraction methods and the respective juices produced was carried out using Kayinja bananas (ABB genotype) imported from Uganda. In the enzymatic extraction process, macerated ripe banana pulp was incubated with a commercial enzyme preparation (Pectinex Ultra SP-L) at 50°C for 2h. In the mechanical extraction process the ripe banana pulp was mixed with stretched strips of polythene and worked with a dough mixer at room temperature for 20min (on average) until the juice appeared. Significantly (p < 0.05) higher 'pure' juice yield (604g kg-1 pulp) was obtained with the enzymatic method than with the mechanical method (541g kg-1 pulp). However, adding water to the spent pulp from the mechanical process and extracting dilute juice improved the juice yield to 757g kg-1 pulp. The enzyme-extracted juice had significantly (p < 0.05) higher soluble solids, titratable acidity, fructose, glucose, total nitrogens density and mineral potassium. However, the mechanically extracted juice had significantly higher sucroses pH and viscosity. Although the mechanical extraction process suffers from occasional juice extraction failures, it offers an opportunity to extract banana juice without excessive energy expenditure, and the juice produced is wholesome with a superior flavour to that produced by the enzymatic method. © 2002 Society of Chemical Industry.