Effect of evaporation on sugar content of coconut water in desiccated coconut industry

Abstract

Coconut (Cocos nucifera L) water is the main constituent in the waste water of desiccated coconut industry. The high COD values of coconut water, 40000 mg/ Z, is the main reason for having significantly high COD levels, 17000-20000 mg/Z, in the effluent which has to be treated to meet the discharge water standards. Coconut water is found to be rich in sugar and nutrition but limited in industrial application due to its low concentration. The volume and sugar concentration of coconuts used in desiccated coconut industry in Sri Lanka was examined and the effect of evaporation on the total sugar content was evaluated. The average volume was found to be 124 mZ/coconut. A significant difference in average sugar concentration was observed for north western region, 32.567g/Z and southern region, 19.455 g/Z. Coconut water was concentrated by evaporating at 3 different pressures; vacuum of 47.4 k Pa, atmospheric pressure of 101.3 kPa and high pressure of 198.6 kPa. Coconut water was sterilized completely during evaporation at atmospheric pressure and high pressure. The degradation of sugar was increased with the increase of both pressure and concentration levels. pH level was decreased and the insoluble solid weight was increased with the increase in concentration level.