During the production of palm sugar, the palm sap (Arenga pinnata) is heated up to 150 degrees C. Besides the hydrolysis of carbohydrate to generate reducing sugars and degradation of amino acid, many physicochemical changes produced at all these temperatures, having a significant impact on the overall quality of palm sugar. In this study, changes in physico-chemical properties of the palm sap due to heat processing were investigated. Analysis of colour, soluble solid, pH, temperature, sugar and amino acid concentration was determinant. The results showed clearly that the heating process at these high temperatures was necessary to create an environment which was rich in essential precursors for subsequent reactions such as Maillard reaction. Chemical compounds that showed drastic changes in concentration were polar side chain amino acids especially glutamine, asparagine and arginine as well as sucrose and pH value. Other quality characteristics of palm sugar based on colour and soluble solids (Brix) shared an increase in concentration as a function of time.
Fucoidan is a sulphated polysaccharide that consists mainly of fucose, normally found in brown seaweeds. In this study, fucoidan was extracted from Sargassum binderi (Fsar) from Malaysia and subsequently characterised. The chemical characteristics of Fsar were found to be different than those of commercial food grade fucoidan (Fysk) and those of previously studied fucoidans. NMR analysis proposed that the main structure of Fsar is →3)fuc-2-OSO3(-)(1→3)fuc(1→. The molecular weight (47.87kDa) and degree of sulphation (0.20) of Fsar were higher than those of Fysk, at 27.98kDa and 0.15, respectively. However, Fsar's polydispersity index (1.12) and fucose content (34.50%) were lower than those of Fysk, at 1.88 and 43.30%, respectively. Both Fsar and Fysk showed similar thermo-gravimetric properties with four mass losses, amorphous in nature and negative optical rotations. Results show that Fsar has fundamental characteristics of fucoidan with different structural conformation i.e. variation in glycosidic linkages and sulphate group orientation.
Fucoidan is a sulphated polysaccharide, made up mainly of l-fucose, which is found in brown seaweeds. Its chemical structure is diverse and depends on maturity, species and geographical location. The objective of this study was to elucidate the chemical structure of fucoidan from Cladosiphon okamuranus harvested in Japan. The fucoidan was subject to purification prior to monosaccharide profiling, sulphate content determination, and linkage analysis. Our results showed that Japanese Cladosiphon okamuranus fucoidan contained 70.13 ± 0.22 wt% fucose and 15.16 ± 1.17 wt% sulphate. Other minor monosaccharides found were d-xylose, d-galactose, d-mannose, d-glucose, d-arabinose, d-rhamnose and d-glucuronic acid. Linkage analysis revealed that fucopyranoside units along the backbone are linked, through α-1,3-glycosidic bonds, with fucose branching at C-2, and one sulphate group at C-4 per every three fucose units, i.e. the structure of fucoidan from Japanese Cladosiphon okamuranus is [→3)-α-fuc(1→]0.52[→3)-α-fuc-4-OSO3-(1→]0.33[→2)-α-fuc]0.14.