Effects of selected preservation techniques on the shelf-life of nipa sap

Nipa sap is a sweet, translucent sap from nipa palm (Nypa fruticans) tree. It is usually consumed as a refreshing beverage by local people. In Sarawak, Malaysia, nipa sap is a raw material to produce nipa sugar or gula apong, a semi-solid sweetener distinguished by its golden caramel colour. It is usually used for making traditional cakes, desserts, sauces and marinades. However, nipa sap usually spoils within 3 hours after collection due to natural fermentation. The present study aimed to enhance the shelf life of nipa sap using several selected preservation methods. The effectiveness of the preservation approaches applied was examined by assessing the physicochemical, microbiological and sensory qualities of nipa sap. The results revealed that high temperature, short time (HTST) pasteurisation and sodium benzoate preservative were able to extend the shelf-life of nipa sap up to 14 days at room temperature. The glucose level was able to be maintained throughout the storage while ethanol concentration was maintained low. For the sensory attributes, HTST showed better acceptance as compared to low temperature, long time (LTLT), sodium benzoate (SB) and citric acid (CA). Local producers can use HTST treatment to extend the shelf life of nipa sap, enabling them to better plan their daily activities and generate more income over an extended period. In addition, the findings will pave the way for the marketability of nipa sap.