Effect of edible coatings on quality parameters and phenol composition of ready-to-eat Salanova lettuce

Minimally processed fresh-cut leafy vegetables are becoming one of the fastest growing segments in the food industry. In this context, new strategies to extend the preservation, such as the application of edible coatings, represent a key issue for the research community. In this study, the effects of emulsion-based edible coatings on the quality parameters of ready-to-eat Salanova lettuce were investigated. The coatings, sprayed on the fresh-cut lettuce, were composed of lemongrass essential oil (0.1%) dispersed in different polymers, such as alginate (ALG), chia mucilage (CM) and chitosan (CHIT). After storage at 4 degrees C for 14 days, the coatings showed similar performance in terms of visual appearance and water loss. Instead, by means of the spectroscopic and HPLC analyses, the ALG coating resulted the most effective in preserving bioactive pigments (chlorophyll and carotenoids) and the phenolic compounds. Specifically, with respect to the initial content of hydroxycinnamic compounds (2.53 mg/g chlorogenic acid equivalents), their depletion was estimated to be 27%, 62%, 79% and 84% in the ALG, CTRL, CM, CHIT samples, respectively.