Cross-linked alginate edible coatings incorporated with hexyl acetate: Film characteristics and its application on fresh-cut rose apple

Abstract

Edible coatings, as carriers of antimicrobial compounds, have been proposed as an alternative method to preserve fresh-cut products. This research focused to improve the shelf life of fresh-cut rose apples by applying an edible coating based on alginate cross-linked with calcium chloride (SAC)-enriched hexyl acetate (HA) as a natural antimicrobial compound. The SAC with HA in 0.01, 0.03, and 0.05% (v/v) (SAC-HA) solution was evaluated for its film properties and applied to fresh-cut rose apples, and compared with the unmodified SAC coating. Postharvest quality and microbial contamination were determined every 2 days during 10 days of storage at 4 °C. The film thickness, tensile strength, and elongation at break increased with the high concentrations of HA added. Films containing 0.03% HA had lower oxygen permeability (from 1.57 to 0.04 × 10−7 cm3 μm m−2 day−1 kPa−1), as well as water vapor permeability (from 0.03 to 0.01 g mm m−2 day−1 kPa−1), compared to the unmodified SAC film. Moreover, the greater coating uniformity and thickness were supported by scanning electron microscopy and Fourier transform infrared spectroscopy. The developed edible SAC coatings with 0.03% HA successfully preserved the physicochemical quality and extended the shelf life of fresh-cut rose apples for 10 days at 4 °C by retarding the respiration rate, inhibiting browning, and preventing microbial growth. Therefore, the using of SAC-HA in fresh-cut products is a promising and safe preservation technique to extend shelf life.