Growth and bioactive phytochemicals in barley (Hordeum vulgare L.) sprouts affected by atmospheric pressure plasma during seed germination

Barley sprouts are 5 to 20 day-old grown whole plants that are widely consumed as a functional vegetable due to their health-promoting compounds such as saponarin, gamma-Aminobutyric acid (GABA), and policosanols. Recent plasma applications have been a promising approach in the agricultural and food industries to produce bioactive phytochemicals in sprouted crops. Therefore, this study investigated the plasma effects on the whole plant and its bioactive phytochemicals compared with those of an untreated control in barley sprouts. The optimal plasma exposure during seed germination can change physical and chemical properties of fully hydrated seeds of barley, accelerate the early growth of its sprouts and enhance bioactive phytochemicals in the sprouts. Thus, a single 6 min exposure of the plasma enhanced the fresh weight of whole barley seedlings by 137.5% of the untreated control at 9 d after the exposure and enhanced the contents of the primary metabolites including soluble sugars and free amino acids, and secondary metabolites including special phytochemicals such as saponarin, GABA, and policosanols. Therefore, our results suggest that the optimal plasma exposure can be used as a promising seed priming technique for the whole plant and the bioactive phytochemicals of barley sprouts.