Impact of argon dielectric barrier discharge cold plasma on the physicochemical and cooking properties of lightly-milled rice

Abstract

This study investigated the influence of argon dielectric barrier discharge-cold plasma (DBD-CP) applied at different voltage settings (1 kV and 2 kV) and exposure durations (5 min and 10 min) on the physicochemical properties, cooking behavior, textural attributes, and flavor characteristics of lightly-milled-rice (LMR). The DBD-CP treatment increased the brightness of untreated LMR from 62.93 to 76.69, and reduced the water droplet contact angle from 66.66° to 58.99° following a treatment of 2 kV-10 min. Moreover, the treatment enhanced the crystallinity and gelatinization enthalpy of LMR starch by 8.93% and 60.55%, respectively. Conversely, it led to a decrease in the amylose content by 7.66% when compared to the control group. Metabolomic analysis revealed a decrease in the content of key compounds involved in metabolic pathways, including amino acids, α-hydroxy acids, and GABA. The cooking experiment demonstrated a substantial reduction by 5.4 min in optimal cooking time, along with water absorption capacity and volume expansion rate increased by 54.19% and 68.42% in 2 kV-10 min DBD-treated LMR, respectively. Notably, DBD-CP treatment positively influenced the production of important aroma compounds such as alcohols, aldehydes, and ketones. Overall, DBD-CP proved to be an effective physical processing method for significantly enhancing the edible quality and aroma of LMR.