Optimization of Vinegar Production from Nipa (Nypa fruticans Wurmb.) Sap Using Surface Culture Fermentation Process

Background and objective: Sap from nipa mangrove palms is rich in nutrition and chemical components. Currently, sap is used for production of fresh juice, syrup, molasses, alcohol and traditional vinegar. The aim of this study was to enhance nutritional values of nipa sap in highquality vinegar using surface culture fermentation. Material and methods: Vinegar was produced from nipa sap using a two-step surface culture fermentation process including vinegar starter culture preparation and vinegar production. Vinegar acetic acid, residual alcohol and pH were optimized. Nipa sap vinegar from surface culture fermentation was compared to that from traditional methods for compliance with regulatory standards. Antioxidant activities (total phenolic content, 2, 2-diphenyl-2picrylhydrazyl radical scavenging and ferric reducing antioxidant power assays) and sensory of the product were assessed. Results and conclusion: Acidity increased to 6.20% using surface culture fermentation at 2.9fold, compared to that using traditional methods (2.14%). Alcohol concentration included 11.9% during wine fermentation. The surface culture fermentation converted alcohol to acetic acid using Acetobacter aceti TISTR 354 in ten days. A good antioxidant activity was reported for the vinegar. Organoleptic properties scored more than “neither like nor dislike” in each attribute. Therefore, high quality vinegars could be produced from nipa sap using surface culture fermentation which could be scaled up in the future. Conflict of interest: The authors declare no conflict of interest.