Palm SapQuality Profiles, Fermentation Chemistry, and Preservation Methods

Palm sap is quite nutritious and highly prone to fermentation. The unfermented juice could be an ideal health drink. Palm sap's quality profile and fermentation chemistry help to predict its shelf life and potential safety. There is demand from farmer-producer companies and food processing industries to develop bottling technology and a transportation/distribution protocol for palm sap similar to common soft drinks. Different techniques were followed for bottling palm sap, but none proved successful at the pilot level or commercial scale. To develop a systemic preservation technique, it is crucial to understand the biochemical composition, fermentation chemistry, and existing preservation methods and their disadvantages. This review mainly focuses on the chemical, microbial, volatiles, and flavor changes of palm sap. In addition to a detailed discussion on contemporary sap preservation techniques, this paper also addresses the effect of pasteurization in combination with preservatives, such as nisin, sodium benzoate, chitosan, potassium sorbate, sorbic acid, citric acid, and sodium metabisulfite, on the shelf life of sap, challenges to preserving palm sap, and future directions for preservation methods.