Microwave pretreated esterification improved the substitution degree, structural and physicochemical properties of potato starch esters. (April 2018)

• Record Type: Journal Article
• Authors: Zhao, Kun; Li, Bei; Xu, Meijuan; Jing, Luzhen; Gou, Min; Yu, Zhezhe; Zheng, Jianmei; Li, Wenhao
• Is Part Of: Lebensmittel-Wissenschaft + Technologie =. Volume 90(2018)
• Page Start: 116
• Page End: 123
• Publication Date: 2018-04
• Subjects: Crystallinity -- Esterification -- Pasting -- Viscosity -- Swelling; Food industry and trade -- Periodicals; Food -- Composition -- Periodicals; Microbiology -- Periodicals; Nutrition -- Periodicals; 664.005
• DOI: 10.1016/j.lwt.2017.12.021
• Languages: English
• ISSNs: 0023-6438

Abstract

Abstract: Potato starches were pretreated with 600 W microwave and then acetylation was carried out with acetic anhydride and glacial acetic acid (1:1 in volume). The microwave-pretreated-acetylation remarkably modified the physicochemical properties of starch compared with the single acetylation method. The starch granules exhibited rough surfaces but maintained integrity and the crystal structure changed to C-type after microwave-pretreated-acetylation. Meanwhile, the microwave-pretreated starch esters exhibited the higher substitution degree, the higher infrared absorption peak intensity and the lower relative crystallinity compared to un-microwave-pretreated ones. The solubility of microwave-pretreated starches was higher at 80–90 °C than un-pretreated samples, while the swelling power of microwave-pretreated starches was lower at 60–90 °C under a same esterification level. Particularly, the solubility of microwave-pretreated samples at 90 °C was 2.11 times higher than un-pretreated ones, while the swelling power of microwave-pretreated starches exhibited 52.8% lower than un-pretreated samples at 90 °C under the 12 mL/100 g esterification level. The peak viscosity and the gelatinization enthalpy of microwave-pretreated starches were lower than un-pretreated ones under the same esterification level. Particularly, these values of microwave-pretreated starches were 2332 mPa s lower and 8.46 J/g lower than un-pretreated ones at the 12 mL/100 g esterification level, respectively. Highlights: Acetylation with microwave pretreatment enhanced the degree of esterification. The starch granules maintained the integrity after treatment. Alterations on starch structural and physicochemical properties are noticeable. The current modification method provides a handy way for industrial production.