Impacts of annealing and acid hydrolysis on physico-chemical properties of cassava starch
2010
Pathama Chatakanonda(Kasetsart University, Bangkok (Thailand). Kasetsart Agricultural and Agro-Industrial Product Improvement Institute) E-mail:aappmc@ku.ac.th | Rungtiva Wansuksri(National Science and Technology Development Agency, Pathum Thani (Thailand). National Center for Genetic Engineering and Biotechnology. Cassava and Starch Technology Research Unit) | Klanarong Sriroth(Kasetsart University, Bangkok (Thailand). Kasetsart Agricultural and Agro-Industrial Product Improvement Institute)
Cassava starches modified by annealing and acid hydrolysis were analyzed for their granular morphology and size distribution, molecular structure and physico-chemical properties. Acid hydrolyzed starch granule surface became slightly roughen with preserved birefringence pattern. Smaller granules were obtained after acid hydrolysis with fragments of granules observed after prolonged hydrolysis for 16 and 32 days. Molecular weight distribution of cassava starch remained unchanged after annealing while degradation of starch components occurred to differing extents after acid hydrolysis. No difference in extent of acid hydrolysis was observed between native and annealed cassava starches. Acid hydrolyzed starches possessed significantly lower pasting viscosity than native and annealed starches. In general, swelling power of cassava starch decreased while solubility increased after longer hydrolysis time. Gelatinization temperatures slightly increased during the first phase of hydrolysis and then decreased accompanying with broader endotherms. Significant increase in gelatinization enthalpy was observed in starch hydrolyzed for 16 and 32 days. The extent of retrogradation of cassava starch increased progressively with decreasing molecular weight of acid hydrolyzed starches. In addition, glass transition temperatures (Tg) of amorphous native and annealed cassava starches at limited moisture were depressed successively with increasing hydrolysis time.
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This bibliographic record has been provided by Thai National AGRIS Centre, Kasetsart University
