Application of Plasma-Activated Water on Lentil Seeds: Germination, Biochemical Changes, and Nutritional Quality Evaluation

This study investigated the impact of plasma-activated water (PAW) treatment on lentil (Lens culinaris) seed germination, with exposure times of 1 to 15 min. PAW generated using an 80% nitrogen and 20% oxygen mixture significantly reduced pH from 7.4 to 2.92 (p < 0.05) and increased nitrate concentration 16-fold after 15 min of treatment, while H2O2 levels remained unchanged (p > 0.05). Ten minutes of PAW exposure yielded the highest rates and sprouts growth (p < 0.05). Protein solubility increased in all PAW-treated samples, peaking at 51% after one minute of treatment (p < 0.05). Phytase and alpha-amylase activities were initially elevated in seeds treated for 1-4 min but declined with longer exposures (p < 0.05), likely due to the change in pH. PAW-10 treatment significantly increased GABA content by four-fold than that in untreated lentils (p < 0.05). Electrophoresis revealed similar protein banding patterns (17-170 kDa) across samples. FTIR analysis indicated the breakdown of structural components in PAW-treated seeds, except for the antiparallel beta-sheet in the control sample. A beta-turn was observed in the treated samples, and beta-sheet aggregates appeared in the 4-min treatment. Nuclear magnetic resonance (NMR) analysis showed the disappearance of alpha C1H and beta C1H anomer signals alongside increased methyl groups. In conclusion, PAW effectively enhances seed germination and nutritional quality, offering a sustainable, innovative method for sprouted seed flour production. However, further research is necessary to optimize industrial scalability and efficiency treatment.