Sustainable Strategies for Extending Strawberry Shelf Life: A Comparative Efficacy of Ultrasonic, Sonochemical, and Chitosan-Based Coatings

Abstract

This study aimed to evaluate the effectiveness of five postharvest treatments ultrasonic bath cleaning (UBC), conventional chitosan coating (CS), sequential UBC followed by CS (UBC + CS), sonochemical coating (SCC), and nano-chitosan coating (CS-NPs) to preserve the quality of strawberries during 20 days of cold storage at 5 ± 1 °C. Nano-chitosan was prepared via ultrasonication and characterized using standard spectroscopic and microscopic techniques. The application of CS-NPs and SCC significantly reduced decay rates to 20% and 25%, respectively, compared to 70% in the untreated control. CS-NPs-treated fruits retained higher anthocyanin content (44 mg/100 g) and maintained sensory acceptability scores above 7.5 even after 20 days, indicating strong consumer appeal. Additionally, weight loss was reduced by approximately 28%, and color brightness (L*) was better preserved compared to conventional treatments. Among all treatments, CS-NPs and SCC were the most effective, reducing weight loss (≤ 20.8%), maintaining firmness (> 2.74 N), and retaining high levels of bioactive compounds and antioxidant activity. So nano-chitosan and sonochemical coatings were the most effective treatments, significantly reducing weight loss and microbial growth while maintaining firmness, color stability, and high levels of antioxidants and bioactive compounds throughout 20 days of cold storage and this study highlights the synergistic benefits of ultrasound-assisted nano-chitosan and sonochemical coatings as sustainable, clean-label strategies for extending strawberry shelf life and maintaining postharvest quality.