The effect of gamma radiation seed priming on glucosinolate metabolism, microbial dynamics, and antimicrobial...

Sprouting boosts bioactive compounds in Brassicaceae, including glucosinolates, amino acids, and anthocyanins. This study examined gamma radiation seed priming effects on growth, metabolism, and bioactive accumulation in Nasturtium officinale, Eruca sativa, and Raphanus raphanistrum sprouts.

Seeds of the three species were primed with gamma radiation (0.1 kGy/h) and grown under controlled conditions. Biomass was measured; metabolic profiling quantified glucosinolates, amino acids, flavonoids, and anthocyanins. Enzymatic activities for glucosinolate and flavonoid biosynthesis were assessed. Antioxidant potential was assessed using FRAP and DPPH assays; antimicrobial activity was tested against Escherichia coli and Enterococcus faecalis. Microbial counts (APCs and Coliforms) were measured.

Gamma radiation increased biomass by 48%, 36%, and 71% in N. officinale, E. sativa, and R. raphanistrum, respectively. Glucosinolates rose, especially glucoerucin (up to 227% in E. sativa) and glucoraphenin (up to 60%), linked to higher precursor amino acids (leucine, tryptophan, methionine), glutathione, and activities of glutathione S-transferase and sulfotransferase. Myrosinase activity increased, boosting sulforaphane. Flavonoids surged: quercetin (48 -191%), kaempferol (75 -172%), anthocyanins (42 -60%), with elevated PAL, CHS, 4CL, and C4H activities. Antioxidant and antimicrobial (40 -77%) potentials improved, though APCs and coliforms rose.

Gamma radiation priming enhances growth, secondary metabolite accumulation, antioxidant potential, and antimicrobial activity in Brassicaceae sprouts. It offers a promising method to improve the nutritional and functional qualities of edible sprouts, aiding food safety and health.