Characterization and efficacy of a composite coating containing chitosan and lemongrass essential oil on postharvest quality of guava

摘要

This study characterized chemical and physical properties of chitosan (Chi) coatings with or without Cymbopogon citratus (D.C.) Stapf. (CCEO) essential oil (0.6 mu L/mL). The effects of Chi-CCEO coating on post-harvest quality of guava during storage (15 days, 12 +/- 1 degrees C) were assessed. CCEO improved thermal resistance and surface properties of Chi-coating. Chi-CCEO coating had low water solubility and a(w), high thermal resistance, smooth and low-roughness surface. Chi-CCEO coating delayed weight and firmness losses, changes in soluble solids, titratable acidity, pH, color and phenolics in guava during storage. Chi-CCEO coating decreased polyphenol-oxidase and pectin-methylesterase activity, while increased peroxidase activity after 5 days. Coated guava had lower fructose content and higher citric and succinic acid content than uncoated guava after 10 days. Coated guava had higher scores for texture, color and overall impression but lower scores for odor. Chi-CCEO coating were effective to maintain guava postharvest quality during a 10 day-cold storage.