The Post-Harvest Application of UV-C Rays: Effects on the Shelf Life and Antioxidants of Fresh Green Asparagus (Asparagus officinalis L.)

UV-C irradiation is an innovative postharvest technique for increasing the safety of fruits and vegetables. This study investigated the effect of UV-C rays (UV-C1 = 0.26 KJ/m2; UV-C2 = 0.40 KJ/m2; UV-C3 = 0.67 KJ/m2; and UV-C4 = 1.34 KJ/m2) on the preservation of the antioxidants, hardness, and color of fresh green asparagus during storage. UV-C1 and UV-C2 significantly maintained higher total phenolic content (10.6%), total flavonoid content (36%), rutin (14.3%), quercetin (27.03%), kaempferol-3-O-rutinoside (21.25%), and antioxidant activity (DPPH 7.5%). Over three weeks of storage, quercetin, ferulic acid, and kaempferol 3-O-rutinoside increased, while rutin and caffeic acid decreased. Storage caused a significant change in the color and hardness of the control sample, but UV-C4 counteracted hardening for up to three weeks, and UV-C3 was the best dose for stabilizing color during storage. This study indicates that the choice of UV-C dose can be modulated based on the characteristics that are intended to be preserved in green asparagus, maintaining a balance between nutraceutical and hedonic characteristics. To maintain the maximum level of nutraceutical compounds over time, UV-C2 can be adopted, while to preserve texture and color, UV-C3 and UV-C4 are a better choice.