Optimizing chitosan-enriched salicylic acid coating to extend the shelf-life of fresh-cut radishes using response surface methodology

Abstract

Chitosan coating and salicylic acid are two widely used preserving methods for fruits and vegetables in postharvest storage, but very limited research can be found on the application of chitosan-enriched salicylic acid (CS–SA) coating for fresh-cut radishes. In this study, three variables (chitosan, salicylic acid, and immersion time) and two responses (whiteness and total bacterial count) were employed to optimize CS–SA process for fresh-cut radishes using response surface methodology. The results showed that the optimal coating process for fresh-cut radishes was 1.0% chitosan and 1.0 mM salicylic acid for 1.8 min. The effects of the optimal CS–SA process on the major storage quality and shelf-life of fresh-cut radishes were also investigated. Results indicated that CS–SA effectively delayed the decrease of whiteness, firmness, ascorbic acid, and total phenolic content in fresh-cut radishes during storage. Meanwhile, CS–SA significantly inhibited the microbial growth and extended the shelf-life of fresh-cut radishes up to 12 days, much longer than those of non- or NaClO-treated ones with 6 and 8 days, respectively. This study suggests that CS–SA is an efficient alternative for the preservation of fresh-cut radish products, and the underlying regulation mechanism of CS–SA on delaying browning and microbial growth is worth further exploration.