Combined Effect of Blue Light and Ethylene Absorber with Chitosan Elicitor Coating on Quality of Feijoa (Acca Sellowiana) Postharvest

Feijoa (Acca sellowiana) fruits have a short postharvest life of approximately 4-5 weeks under cold storage. This study, conducted in December 2023, used a completely randomized design (CRD) in a factorial arrangement to evaluate the effects of blue light exposure (6, 12, or 24 h), chemical elicitors [chitosan (CS), alginate (A), or putrescine (P) at 2 mg L⁻¹], and ethylene absorbers [none (E0), zeolite (E1), or biochar (E2)] on fruit quality during storage at 4 °C and 90-95% RH. A total of 36 treatment combinations, each with three replications (three fruits per plot), were tested on 324 fruits from uniform, commercially mature trees (~6.5 °Brix). Fruits were immersed in elicitor solutions for 30 min, dried, and exposed to blue light (λ = 470 nm) for the assigned duration before storage with or without ethylene absorber sheets characterized via BET and SEM. Quality parameters assessed included durability, respiration rate, ethylene emission, decay, firmness, weight loss, chlorophyll, ion leakage, and chilling. The combination CSE2L6 (CS + biochar + 6 h blue light) extended durability to 62/25 days compared with 31 days in the control and shelf life 216/25 hours, reduced decay by 64%, and decreased respiration rate and ethylene emission by 48% and 52%, respectively. These results demonstrate that integrating edible coatings, short-duration blue light, and ethylene absorbers can substantially extend storage life and maintain physicochemical quality in feijoa, providing an eco-friendly postharvest management strategy.