Radiation-induced priming: enhancing the nutritional, medicinal, and antioxidant properties of sesame sprouts

This study aimed to assess the individual and combined effects of helium-neon laser and ultraviolet (UV) radiation seed priming on the growth, nutritional quality, metabolic activity, and functional properties of sesame sprouts.

Sesame seeds were subjected to helium-neon laser, UV radiation, and a combined UV + laser treatment. Post-priming, sprout growth parameters were measured, along with chlorophyll, carotenoid, and nutrient levels. Enzymatic activities of nitrate reductase (NR) and glutamine synthetase (GS) were evaluated, as well as the content of amino acids, proteins, lipids, and a range of secondary metabolites. Antioxidant capacity was assessed using the ferric reducing antioxidant power (FRAP), the diphenylpicrylhydrazyl (DPPH), and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay. Antidiabetic and antimicrobial properties were also examined; along with changes in microbial populations (aerobic plate counts [APCs] and coliforms).

The combined UV + laser treatment significantly increased fresh weight and pigment content. Nitrogen assimilation was enhanced via higher NR and GS activities, leading to increased synthesis of glutamine and glutamate. Radiation priming elevated the levels of proteins, lipids, and secondary metabolites including alkaloids, polyphenols, flavonoids, saponins, and glycosides. Phenolic compounds were especially abundant under the combined treatment, indicating activation of phenylpropanoid and shikimate pathways. Antioxidant potential improved significantly, as did antidiabetic activity through enhanced α-amylase and α-glucosidase inhibition and a lowered glycemic index. The combined treatment also exhibited the strongest antimicrobial activity and increased counts of APCs and coliforms.

Helium-neon laser and UV radiation seed priming, particularly when combined, promotes sesame sprout growth and enhances nutritional, antioxidant, antidiabetic, and antimicrobial properties. These findings highlight the synergistic potential of abiotic stress priming as a sustainable strategy to improve the functional value of plant sprouts for food and health applications.