Applications of carboxymethyl cellulose- and pectin-based active edible coatings in preservation of fruits and vegetables: A review

The perishable nature of fruits and vegetables makes their shelf-life limited. Environmental factors, transportation and preservation conditions through postharvest could decrease the storage time and quality. Therefore, prolonging supply time of fruits and vegetables by safer postharvest treatments direct the preservation methods to edible coatings. Active edible coatings incorporating different types of functional substances can be used as a preservation method to boost strategies in improving quality, safety and shelf-life of fruits and vegetables upon storage. This review attempts to present a complete overview of carboxymethyl cellulose (CMC) and pectin as a basis for edible coatings and recent developments related to their application as active coatings for preservation of fruits and vegetables quality. CMC and pectin are two main polysaccharides with great potential in making edible coatings. The CMC- and pectin-based edible coatings are commonly odorless, tasteless, non-toxic, non-allergic, water-soluble, transparent and resistant to oil and fats. CMC and pectin, additionally, could be good carriers for active additives. In this sense, CMC and pectin-based active coatings could provide a great potential both for their protective effect and carrying functional compounds such as antimicrobials, antioxidants, anti-browning agents, texture enhancers and nutraceuticals into their coating matrix to prevent unwanted reactions (e.g., microbial growth, oxidation, enzymatic browning and softening) in horticultural products. Such strategy could inhibit microbial decays and enzymatic or biochemical damages and prevent physical or textural deteriorations in fruits and vegetables during storage.