An ecofriendly edible coating using cashew gum polysaccharide and polyvinyl alcohol

Abstract

Interest in food safety and plastic waste reduction has led to an increase in the search for biopolymer-based coatings within the food industry. The feasibility of preparing an edible coating based on cashew gum polysaccharide (CGP) and polyvinyl alcohol (PVA) was studied. A CGP/PVA coating was characterized for structural, mechanical, barrier and optical properties. Additionally, CGP/PVA edible coatings were bioactivated by immobilization in the film of cell wall degrading enzymes (TCWDE) and applied to the surface of fresh strawberries for evaluation of its fungal growth inhibition capabilities. Scanning electron microscopy results showed that the structure of the CGP/PVA coating was homogeneous without rough surfaces or pores. The CGP/PVA edible coating showed 88% light transmission, a tensile strength of 0.04 MPa, 147% elongation at break and water vapor permeability of 7 x 10−11 g m−1s−1Pa−1. Additionally, it was shown that CGP/PVA and CGP/PVA/TCWDE coatings reduced strawberry-related weight loss and inhibited fungal proliferation. These results suggested that the CGP/PVA hydrogel is a promising material for production of edible antimicrobial coatings.