Wax was the first edible coating used on fruits and vegetables. The Chinese applied wax coatings to oranges and lemons in the twelfth and thirteenth centuries (Hardenburg, 1967). Although the Chinese did not realize that the full function of edible coatings was to slow down respiratory gas exchange, they found that wax coated fruits could be stored longer than non-waxed fruits. In the 1930s hot-melt paraffin waxes became commercially available as edible coatings for fresh fruits such as apples and pears. Erbil and Muftugil (1986) reported that coating peach surfaces with wax emulsions decreased water vapor and oxygen transmission thus, diminishing the respiration rate and increasing shelf-life of the fruit. Nisperos-Carriedo et al. (1990) observed that oils or waxes and cellulose had similar effects in preventing spoilage and retaining the fresh-picked quality for tropical fruits.
Several attempts have been made to develop other materials that could be used to coat produce and modify internal gas composition for short-term storage. Zhang and Quantick (1997) suggested that chitin and chitosan (deacetylated chitin) from marine invertebrates could be used to make a transparent film for application as an edible coating on fruits and vegetables. In 1982, Lowings and Cutts (1982) reported an edible coating material that is non-phytotoxic, tasteless, odorless and effective in preserving fruits. This coating material is a mixture of sucrose fatty acid esters (SFAE), sodium carboxymethyl cellulose and mono-and diglycerides. SFAE was originally developed as an emulsifier. However, it has been established that the ripening of fruits can be retarded by a coating of SFAE. SFAE mixtures have been commercially available for coating fruits and vegetables since the 1980s, under the trade names 'TAL Pro-long' and 'Semperfresh' (Banks, 1984; Chu, 1986; Santerre et al., 1989). Park et al. (1994b, c) applied zein coating to the surface of tomatoes and reported that the film coating delayed color change, weight loss and maintained firmness during storage.
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