Surfactant-enhanced chitosan coating extends postharvest shelf-life of Keitt mango
Elham Tavassoli-Kafrani, T.V. Gamage, Lingxue Kong, T. K. Singh, Shuaifei Zhao
Abstract
The surface properties of Keitt mango and wettability of chitosan (CH) coatings containing ethyl lauroyl arginate (LAE, an ionic surfactant), and sucrose monolaurate (SML, a non-ionic surfactant) were investigated. The Keitt mangoes were coated with different chitosan-based solutions and stored at room temperature (25.0 ± 0.6 °C) for 35 days. The Keitt mango surface had low surface energy (<100 mN/m) with high dispersive component (17.70 ± 1.49–22.86 ± 1.02 mN/m). SML and LAE surfactants significantly (P < 0.05) lowered the surface tension of the CH coating solution by 6.94, and 24.13 mN/m, respectively. As a result, the wettability of CH based coating on mangoes was improved to −68.37 ± 0.01 mN/m (CH-SML), and −30.29 ± 0.00 mN/m (CH-LAE) compared with CH (−76.45 ± 0.04 mN/m), resulting in smooth and homogeneous coatings. The storage test results indicated a significant reduction (P < 0.05) in disease incidence and weight loss by the CH-SML and CH-LAE coatings and the coated mangoes were firmer with lower pH values compared with the control. This study suggests that CH-LAE and CH-SML coatings can effectively extend the shelf-life of Keitt mangoes by 10 and > 15 days, respectively. • Keitt mango surface has low energy with high dispersive component. • Surfactants enhanced wettability of chitosan coating on mango. • Chitosan-surfactant coating delayed mango ripening. • Chitosan-sucrose monolaurate coating showed the best overall performance.