Preparation and characterization of polyphenol-chitosan conjugate-eugenol essential oil microcapsule and its effect...

Given the high volatility, low water solubility, and oxidative sensitivity of essential oils, this study synthesized microcapsules of essential oil (EEO) (quercetin-chitosan-EEO [QE-CS-EEO]) using a QE-CS graft copolymer as the wall material and EEO as the core material. Research findings indicate that QE-CS exhibits superior in vitro antioxidant activity, with scavenging abilities for 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ABTS+ radicals being 58.71% and 77.03% greater than those of CS, respectively, thereby providing more effective protection for the essential oil. In comparison to CS essential oil, microcapsules (CS-EEO), QE-CS-EEO demonstrated an 18.65% increase in EEO encapsulation efficiency, achieving a total encapsulation efficiency of 41.29%. Based on these results, various edible coating solutions were formulated, including Control, E1 (1% CS), E2 (0.5% CS + 0.5% CS-EEO), E3 (0.5% CS + 0.5% QE-CS-EEO), and E4 (1% EEO), to extend the shelf life of cherry tomatoes. Notably, cherry tomatoes treated with the E3 formulation maintained superior freshness indicators, exhibiting an extended shelf life of approximately 9-12 days compared to the control group. This study aims to explore a novel microcapsule wall material and provide a strategy for extending the shelf life of fruits and vegetables, thereby minimizing food waste.