The effects of dielectric barrier discharge plasma on physicochemical and digestion properties of starch

Abstract

The effects of dielectric barrier discharge (DBD) plasma treatment on physicochemical and digestion properties of Tartary buckwheat (TBS), sorghum (SS), wheat (WS) and quinoa (QS) starches were investigated. Plasma treatment resulted in higher solubility and lower swelling capacity of the starch samples studied. Through XRD and FTIR analyses, the relative crystallinity of starch was increased by DBD plasma, while the crystalline type remained unchanged. It was observed from SEM that more fissures and holes appeared for TBS and SS granules, and granule aggregation occurred for WS and QS caused by plasma treatment, both of which made digestion enzymes more accessible to the four starches. In addition, a marked increase in gelatinization temperature and significant reduction in viscosity of plasma treated starches were found. Interestingly, the increased enzyme accessibility and decreased viscosity of starch were consistent with the enhanced starch digestibility that was suggested by the increased RDS content, digestion rate and digestion velocity constant. Therefore, the DBD plasma treatment on starch may be not in favor of postprandial blood sugar control, but it is suggested to be applied in some industrial processes that need acceleration in starch hydrolyzation, such as bioethanol production, brewing and food fermentation.