Impact of ultrasound on postharvest physiology and bioactive compounds of sweet basil during short-term storage

Sweet basil is a perishable green herb that has a short shelf life after harvest. Techniques to extend its shelf life and prolong its storability may be commercially beneficial. In this study, the impact of different ultrasound powers on the postharvest quality and bioactive compounds of sweet basil during storage was investigated. The sampled basil leaves were immersed in an ultrasonic bath (40 kHz) at 200 or 400 W for 3 min at ambient temperature (28 ℃). The control samples were treated with tap water. All of the treatments were packed in a basket covered with a polyethylene sheet and kept at 13 ℃. Changes in the physical and chemical properties were recorded every 3 h to determine the impact of the ultrasound treatment on prolonging the postharvest quality and maintaining the bioactive compounds of the sweet basil leaves. The results showed that ultrasound at 400 W significantly reduced the weight loss and respiration rate of the sweet basil leaves. Additionally, ultrasound at 400 W increased the total phenolics, total flavonoids, antioxidant activity, and vitamin C content, which were related to the activity of phenylalanine ammonium lyase and ascorbate peroxidase, compared with the control. This study showed that ultrasound treatment can delay postharvest loss and maintain the nutritional quality of sweet basil during storage.