Effect of additives on the quality of tender coconut water processed by nonthermal two stage microfiltration technique

Abstract

Non-thermal two-stage microfiltration technique in aseptic conditions was used to preserve coconut water. Concentrations of citric acid (0.02 g/100 mL), ascorbic acid (0.18 g/100 mL) and l-cysteine (0.009 g/100 mL) were standardized according to taste and added to coconut water as natural additives. The coconut water was packed in glass and plastic bottles after flushing the headspace with nitrogen and stored under refrigeration (4 °C). The microfiltered water was studied for microbial, sensory and physicochemical properties for a period of 46days. The quality of the water packed in glass bottles was better in all respects. The total soluble solids changed from 5.4 to 6°Brix. The pH changed from 5.7 to 5.8. The soluble sugar concentration increased from 1.9g/100 mL to 3.1 g/100 mL, free fatty acid content increased from 0.064 mg KOH/g to 2.8 mg KOH/g at the end of 46days, which was much lower than the changes in control. The protein content decreased in all the samples. Two way ANOVA showed that the storage time had more impact on the sensory properties of the product than the packaging material. The glass bottled product was acceptable on sensory basis till 46days of storage.