Effect of preservative and preservation methods on physical, chemical and microbiological properties of nipa palm (Nypa fructicans) sap

Abstract

Objectives Nipa palm sap that has undergone fermentation is creamy white in colour with an unpleasant aroma and taste, which makes it unacceptable for consumption. This study aimed to evaluate the effectiveness of the E’ food grade preservative – potassium sorbate (E202) and sodium metabisulfite (E223) to extend the shelf-life of nipa palm sap, hence determining the effects of different preservation methods on its sucrose content and total bacterial count (TBC). Results The result showed that samples during post-sap collection were found more susceptible to microbial growth and contamination than those samples for pre-sap collection. Upon collecting, the initial pH of Sample A was higher (6.33) than Sample B (5.52) and control sample (5.52). Meanwhile, the TBC were the highest in the control sample (2.83 x 105), followed by Sample B (1.14 x 105) and the lowest TBC were in Sample A (1.03 x 105). Conclusion Compared to utilizing either potassium sorbate or sodium metabisulfite alone, the combination of the two proved to be far more successful in preserving the palm sap and adding it during pre-sap collection was found more effective to slow down the natural fermentation, rendering longer keeping quality up to 8 hours ensuring colour, flavour and aroma.