title: Physicochemical, morphological, thermal and IR spectral changes in the properties of waxy rice starch modified with vinyl acetate.
abstract: Waxy rice starch was modified with vinyl acetate at levels of 4, 6, 8, and 10 % with degree of substitution of 0.021, 0.023, 0.032 and 0.056. The modified starches were studied for physicochemical, morphological, thermal and infra red spectral properties. Waxy starch acetates had high water holding capacity and did not sediment. Scanning electron microscopy revealed surface damage of the granules and their fusion. X ray diffractography showed that crystalline peak intensity had increased on acetylation. Differential scanning calorimetry studies showed changes in thermal properties. While gelatinization temperatures of modified starches were higher than the native starch, their transition enthalpies were lower than the native starch. IR spectra of the starch acetates did not show the peak typical for acetyl group. Thus, modification of waxy rice starch with vinyl acetate caused changes in the starch properties. The high water holding capacity of starch acetates can be exploited for specific applications.
authors.affiliation: Department of Food Engineering and Technology, Tezpur University, Tezpur, 784 028 India.
authors.forename: Dipankar
authors.initials: D
authors.lastname: Kalita
authors.affiliation: Department of Agricultural & Food Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721 302 India.
authors.forename: Neelima
authors.initials: N
authors.lastname: Kaushik
authors.affiliation: Department of Food Engineering and Technology, Tezpur University, Tezpur, 784 028 India.
authors.forename: Charu L
authors.initials: CL
authors.lastname: Mahanta
keywords: FT-IR; Physicochemical properties; SEM; Vinyl acetylation; Waxy rice starch; XRD