Effect of natural deep eutectic solvents on thermal stability, syneresis, and viscoelastic properties of high amylose starch

Int J Biol Macromol. 2021 Jul 21:S0141-8130(21)01550-6. doi: 10.1016/j.ijbiomac.2021.07.099. Online ahead of print.ABSTRACTThis work aimed to use natural deep eutectic solvents to modify the thermal, textural, freeze-thaw, and rheological properties of high amylose rice starch. Three different natural deep eutectic solvents (NADES) composed of sugar and organic acids were applied to modify the properties of starch dispersion. In presence of NADES, the onset temperature of starch was decreased, in comparison with starch in aqueous and glycerol medium. During thermal decomposition, starch with the aqueous and glycerol systems showed two-step weight losses whereas with NADES starch showed single-stage weight losses or decomposition. Moreover, negligible syneresis was observed for starch-NADES dispersion after 3rd cycle of the freeze-thaw process. The flow behavior of starch-NADES dispersion follows Herschel-Bulkley models as R2 (0.996 ≤ R2 ≤ 0.999) are higher than the Mizrahi-Berk model. The flow behavior index (n) of starch-NADES dispersion was closer to 1, indicated a nearly Newtonian fluid. The loss modulus (G″) value of starch-NADES dispersions was markedly higher than the corresponding storage modulus (G') value and thus materials behaved like viscoelastic liquid. The present study manifested a green way to modify the properties of the high amylose starch to improve the processing stability.PMID:34302868 | DOI:10.1016/j.ijbiomac.2021.07.099

Source: International Journal of Biological Macromolecules - July 24, 2021 Category: Biochemistry Authors: Vivek Gupta Rahul Thakur Amit Baran Das Source Type: research