a b s t r a c tCombinations 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.

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This study was conducted to evaluate color and anthocyanin stability of clarified acerola juice (CAJ) as affected by montmorillonite (Mnt) at different concentrations (0-6 wt%, dry basis). While non-complexed CAJ suffered noticeable color degradation with time and pH variations, the presence of Mnt (especially at 4-6 wt%) not only changed the initial color of CAJ but also made it more stable with time and pH changes. CAJ/Mnt mixtures were ultracentrifuged in order to separate them into supernatants and anthocyanin-complexed Mnt precipitates. The supernatants presented decreasing anthocyanin contents with increasing Mnt concentrations, indicating pigment retention by the precipitates. X-ray diffraction of precipitates showed that Mnt interlayer spacing was increased by increasing anthocyanin/Mnt ratios, corroborating anthocyanin intercalation. FTIR revealed a band at 1530 cm ascribed to formation of anthocyanin-Mnt complexes. Moreover, chromatograms indicated the selective adsorption of two compounds by Mnt, which were identified by LC-MS as cyanidin-3-O-rhamnoside and pelargonidin-3-O-rhamnoside.

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Summary Properties of glycerol‐plasticised cassava starch–carnauba wax emulsion films were studied as functions of carnauba wax/starch (CW/S) ratios. Increases in CW concentrations improved elongation, but impaired tensile strength and elastic modulus, suggesting a plasticising effect by CW and/or the emulsifier. CW reduced water solubility of the films and decreased their water vapour permeability (WVP) up to CW/S ratios of 0.15–0.20, probably because of the decreased water solubility. Higher CW concentrations resulted in increased WVP, possibly due to starch matrix loosening. The opacity imparted by high CW concentrations in films could compromise some applications. The Tg of starch and the expected CW effects on it were not evidenced by DSC thermograms, but CW seems to have affected starch crystallisation, maybe by forming complexes with amylose and/or amylopectin.