Nanoreinforced alginate–acerola puree coatings on acerola fruits

Abstract

Combinations of fruit purees with polysaccharides have been explored to produce edible films and coatings. In this study, the combination between acerola puree and alginate was reinforced with cellulose whiskers (CW) or montmorillonite (MMT) to form nanocomposite edible films (casted on glass plates) and edible coatings (applied on acerola fruit surfaces). Three film/coating dispersions were formulated, based on unfilled alginate–acerola puree (AA), CW-reinforced alginate–acerola puree (CWAA), and MMT-reinforced alginate–acerola puree (MMTAA). Both nanofillers (CW and MMT) reduced water vapor permeability (WVP) of films. When applied to fresh acerolas, the coatings decreased fruit weight loss, decay incidence, and ripening rates. Ascorbic acid retention by the fruits were favored by the coatings, especially the nanocomposite ones. The MMTAA coating was the most effective in reducing weight loss of acerolas. Moreover, it was the coating which best maintained its red color and the visual acceptance of coated acerolas.