Effect of Heating Processes on Physical and Chemical Properties of Syrup from Sap of Nipa Palm (Nypa fruticans Wurmb.)

摘要

The purpose of this research was to improve the color quality of syrup production from nipa sap by optimized heating process. The treatment of heating at 100 degrees C until the sap concentrated to 48 oBrix, followed by reducing temperature to 80 degrees C until the sap reached 68 oBrix, was a preferred method to syrup production. The browning intensity of syrup was 2.08 and the HMF (5-hydroxymethyl-2-furfural) was 16.28 mg/kg. It was noticed that nipa syrup contained high sugar and small amount of salt (2.38%, db) due to area-based growth. Panelists accepted the syrup product by giving a 9-point hedonic scale of 6.81, 6.80, 7.01, 6.67 and 6.91 for color, odor, viscosity, taste, and overall liking, respectively. After storage for 12 weeks, the pH and acidity were not significantly changed. The viscosity decreased, including L* and b* except a*. Total microbial count as well as yeast and mold were less than 10 CFU/g, and the MPN of Escherichia coli was identified less than 3/g.