Effect of cashew gum-carboxymethylcellulose edible coatings in extending the shelf-life of fresh and cut guavas

Abstract

Cashew gum (CG) and carboxymethylcellulose (CMC) based formulations have been evaluated as protective edible coatings on intact and cut red guavas. Samples were coated by dipping in aqueous mixtures of 1% CG and 1% plasticizer (glycerol) for CMC additions of 1 and 2% wt. The fruit was stored at ambient conditions (25–28 °C, 76.0 ± 12.4% RH), and loss of mass, color of pulp and peel, and texture were assessed. Magnetic Resonance Imaging (MRI) was used to visualize the internal structure decay of the intact fruits. Both coatings resulted in a reduction of mass loss, preserving firmness and delaying skin color changes. When comparing after 12 day storage, the mass loss in cut coated samples (CG plus 2% wt of CMC) was 38.5% inferior than that measure to uncoated references. At large, both coating formulations reduced water loss and changes in color of the cut surfaces. MRI analysis showed that tissue decay took place mainly near the peel or around the peduncle region between 8 and 12 days of storage at room temperature.