Process optimisation for enzymatic clarification of indigenous wild watermelon (Citrillus Lanatus) juice

Abstract

Tailored wild watermelon (Citrullus lanatus) juice clarification process is a fundamental step in improving its appearance and consumer acceptability. The purpose of this research was to investigate the mineral and proximate composition of wild watermelon juice (Citrullus lanatus) and to design an optimum processing condition for the enzymatic clarification of the juice. This investigation will help identify the sustainable processing parameters (incubation time, incubation temperature, and enzyme concentration) for ultimate clarification. Wild watermelon juice was treated with pectinase enzyme at different concentrations (0.05 to 0.15 w/w%), incubation temperatures (30 - 50 ͦ C), and incubation times (60 - 180 min). The different process parameters were utilised with each sample treated individually to determine their effect on selected responses: turbidity, clarity, viscosity, L* value, and brix. It was determined that the incubation temperature was the most crucial factor affecting the physiochemical properties of the juice as it exerted a significant influence on most (turbidity, absorbance, and viscosity) of the clarity attributes of the juice. Incubation time significantly affected turbidity and percent brix, whereas enzyme concentration only significantly affected percent brix of the juice. The optimum conditions for juice clarification were established by the Response Surface Methodology at the following parameters: enzyme concentration 0.15 w/w%, incubation time 60 min, and incubation temperature 60 ͦ C. The optimum output parameters at the following: turbidity: 14.18 NTU; clarity: 0.04 Abs; colour: 52.30 L value; viscosity: 1.96 cps; brix: 3.08 %. It may be useful to investigate the optimum parameters for other juices.