Physicochemical properties and nutritional compositions of nipa palm (Nypa fruticans Wurmb) syrup

摘要

Nipa palm ( Nypa fruticans Wurmb.) syrups from three geographical plantation sites in Nakhon Si Thammarat, Southern Thailand were characterized for their physicochemical properties and nutritional values. Variations in color, clarity, viscosity, pH, total soluble solid, total acidity, salinity, water activity, browning intensity and 5-hydroxymethylfurfural content of the syrups were observed among the plantation areas. The nutritional compositions of the syrups also varied depending on their harvested locations. Sugar was the main dry matter presented in all the nipa palm syrups, followed by protein and ash. The energy values of the syrups were in the range of 376–413?kcal/100?g, dw. Sucrose was found as a major sugar in all syrup whereas glucose and fructose were found as minor sugars. Low amounts of natural fructan, fructo-oligosaccharide, and kestose were found only in one plantation area. The total phenolic acid and total flavonoid contents were determined in all syrup with varying concentrations. Potassium and sodium were found as major elements. Phosphorus, magnesium, silica, calcium, iron, copper, iodine, manganese, zinc, and chromium were also found at varying contents. Sugar derivatives, non-protein nitrogenous compounds, polyphenols, organic acids, and some flavor substances were identified in the nipa palm syrups by liquid chromatography-mass spectrometry. Results highlighted the variations in physicochemical properties and nutritional compositions of nipa palm syrup. Overall, the nipa palm syrup can be regarded as an alternative sweetener for application in the functional food formulations.