Edible Coating on Almond and Walnuts Fruits
Almonds and walnuts are nutritionally valuable nuts; however, their quality can deteriorate during storage due to moisture transfer, lipid oxidation, rancidity, and microbial growth. Edible coatings have attracted increasing attention as a potential approach to maintaining the quality and extending the shelf life of these products. This review aims to summarize recent research on edible coating materials and their applications in preserving the quality of almonds and walnuts. Relevant literature published from 2013 onward was searched using Google Scholar, Science Direct, and Scopus. Following the search and screening process described in the reviewed article, 35 articles addressing edible coatings for nuts were selected for information collection and analysis. The reviewed studies covered four main categories of coating materials: lipids, polysaccharides, proteins, and composite formulations, as well as emerging applications involving nanotechnology. The findings reported in the reviewed literature indicate that different edible coatings can help reduce moisture transfer, delay lipid oxidation and rancidity, limit microbial growth, and preserve the sensory characteristics of almonds and walnuts during storage. Polysaccharide-based coatings, including those containing chitosan, starch, and cellulose derivatives, were associated with improved quality preservation, while lipid-based coatings provided moisture-barrier properties. Protein-based and composite coatings also showed potential for maintaining sensory quality and reducing oxidative deterioration. Furthermore, studies involving Nano-enabled packaging reported improvements in shelf life and microbial control, although further investigation of nanoparticle migration and potential human-health effects is necessary. Overall, edible coatings represent a promising approach to improving the storage stability and quality of almonds and walnuts. However, their effectiveness depends on the coating formulation and storage conditions, highlighting the need for further research to optimize their application and assess their safety.