Optimisation of low temperature extraction of banana juice using commercial pectinase

• Low temperature and low enzyme based extraction for banana juice is outlined.
• Incubation temperature 33 °C, time 108 min and concentration of the enzyme 0.03% v/w.
• High amount of potassium (1400–1630 mg/l) was obtained in the extract.
• Depectinization kinetics followed first order kinetics.

The objective of this work was to develop a process with optimum conditions for banana juice. The procedure involves hydrolyzing the banana pulp by commercial pectinase followed by cloth filtration. Response surface methodology with Doehlert design was utilised to optimize the process parameters. The temperature of incubation (30–60 °C), time of reaction (20–120 min) and concentration of pectinase (0.01–0.05% v/w) were the independent variables and viscosity, clarity, alcohol insoluble solids (AIS), total polyphenol and protein concentration were the responses. Total soluble sugar, pH, conductivity, calcium, sodium and potassium concentration in the juice were also evaluated. The results showed reduction of AIS and viscosity with reaction time and pectinase concentration and reduction of polyphenol and protein concentration with temperature. Using numerical optimization, the optimum conditions for the enzymatic extraction of banana juice were estimated. Depectinization kinetics was also studied at optimum temperature and variation of kinetic constants with enzyme dose was evaluated.