Impact of dielectric barrier discharge cold plasma on functionality and starch properties of germinated sorghum

Abstract

This study investigated the synergistic effects of dielectric barrier discharge cold plasma (DBD-CP) pretreatment and germination on enhancing the physicochemical and functional properties of sorghum. DBD-CP treatments were applied under varying voltages and durations 25 V and 50 V for 5 and 10 min followed by a three-day germination process. Results demonstrated that DBD-CP induced surface etching and micro-cracks on seed coats, enhancing hydrophilicity and water uptake. This modification significantly improved germination rates, with the highest rate of 82.0 % observed under 25 V-10 min treatment compared to 68.7 % in untreated controls, alongside a marked increase in seedling vigor index from 192.4 to 913.0. Germination alone reduced anti-nutritional tannin content by approximately 30 %, while DBD-CP pretreatment further enhanced starch properties, elevating relative crystallinity from 26.0 % in germinated controls to 54.0 % and improving short-range molecular order. Metabolomic profiling revealed that plasma treatment modulated key metabolic pathways, including carbohydrate and amino acid metabolism, with γ-aminobutyric acid content peaking under 25 V-10 min conditions. These findings highlight DBD-CP as an effective non-thermal technology to optimize germination outcomes, enhancing sorghum's nutritional quality, digestibility, and bioactive compound profiles for functional food applications.