Wednesday, May 28, 2008

Some characteristics of cross-linked hydroxypropyl sago starch


Sago starch was laboratory hydroxypropylated using 1% propylene oxide in alkaline condition, then cross-linked using 0.000-0.025% phosphorus oxychloride. The dual modified starches with level of cross-linking ranging from 0.0000 to 0.0186 were characterized for amylographic properties, swelling power, paste turbidity and in vitro digestibility using porcine pancreatic alpha-amylase. The cross-linking procedure applied to dual modification nearly unchanged the pasting temperature, i.e. at 62.5drajatC. Cross-linked, hydroxypropyl starches with DS more than 0.0150 had similar amylographic properties which showed high heat and shear stability of the paste. Cross-linking resulted in decrease in the swelling power and the in vitro digestibility of the starch. Hydroxypropylation prior to subsequent modification facilitate the cross-linking with a consequence of lower pasting temperature, higher maximum viscosity, higher swelling power and lower digestibility. Haryadi and Kapti Rahayu Kuswanto; Faculty of Agricultural Technology, UGM

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