This study aimed to evaluate the influence of films based on chitosan and rosemary extract on the physicochemical, microbiological, and oxidative characteristics of beef. Refrigerated steaks of Longissimus dorsi were distributed in a factorial arrangement (4 × 4) into four treatments consisting of four edible films (control; chitosan; chitosan + 4% rosemary extract; and chitosan + 8% rosemary extract) and four days of aging (0, 2, 4, and 8 days). Incorporating 4% or 8% rosemary extract into the chitosan film improved the characteristics of the films in terms of moisture absorption and elasticity. The edible coatings with chitosan and rosemary extract and the different days of aging increased the tenderness and decreased the lipid oxidation of beef. In addition, the chitosan films containing rosemary extract increased the water-holding capacity and decreased the cooking losses of beef. The films containing 4% and 8% rosemary extract decreased the development of mesophilic and psychrotrophic bacteria and Staphylococcus ssp. in beef. We recommend incorporating 4% rosemary extract into chitosan-based coatings to preserve the quality of refrigerated beef.

Mango is a climacteric fruit that requires efficient postharvest technologies to maintain quality during storage and transportation. This study aimed to investigate the effect of biodegradable packaging from chitosan (CS) incorporated with graphene oxide (GO) on the quality, bioactive compounds and antioxidant activity of cold-stored ‘Tommy Atkins’ mangoes. Mangoes harvested at physiological maturity were stored without packaging or in CS, CS-GO or non-biodegradable polyethylene (PE) packaging at 12.0 °C and 89% relative humidity for 42 days. The results show that GO improved the water barrier and mechanical properties of CS packaging. All packaging delayed fruit ripening by reducing the respiration rate, mass loss, softening and changes in color, soluble solids, titratable acidity and beta-carotene content, also preserving the mangoes’ visual appearance. In addition, all packaging maintained higher ascorbic acid, yellow flavonoid, phenolic compounds and antioxidant activity levels in the fruit, compared to non-packed ones. Chitosan packaging is a promising, eco-friendly alternative for the preservation of quality, bioactive compounds and antioxidant activity of cold-stored ‘Tommy Atkins’ mangoes, extending their postharvest life by at least 14 days.

Yellow or sour passion fruit is a climacteric fruit with a high rate of respiration and ethylene production, and postharvest technology is needed to extend its shelf life. This study investigated the properties of a biocomposite film with chitosan (CH) incorporated with beeswax (BW) and graphene oxide (GO) nanoparticles for use as an edible coating to extend the shelf life of yellow passion fruit at 22 °C and 70% RH for eight days. CH films associated with BW showed lower water vapor permeability (WVP) than films with CH alone. However, adding GO to the CH + BW biopolymer matrix improved the WVP, decreased the solubility (12.8%), and increased the opacity of the film by 9% compared to those of the CH film. Fruits coated with CH + BW or CH + BW + GO exhibited a reduction in respiration rate, a slower ripening process by approximately 3 days, and a significant decrease in weight loss. This also resulted in a higher soluble solids content and increased antioxidative capacity of the pulp. The incorporation of GO into the CH + BW matrix resulted in a more pronounced delay of fruit ripening, as evidenced by the lower depigmentation of the peel at eight days, with a lightness approximately 10.7% lower at 54.92, a chroma value 16.5% lower at 49.33, a hue angle 7.2% higher at 92.56, a soluble solid (SS) content 16.7% higher at 11.32°Brix, and an acidity 31.9% higher at 4.18% compared to the control. Furthermore, the biopolymer packaging led to a higher consumer acceptance score for the fruit.

RESUMO Filmes biopoliméricos podem substituir vantajosamente polímeros de origem petroquímica em diversas áreas, como a de embalagem de frutas e hortaliças. Como esses produtos apresentam respiração e transpiração mesmo após a colheita, as propriedades de barreira e de resistência à água do material são cruciais para o cumprimento de seu propósito. Neste trabalho foram obtidos filmes biopoliméricos baseados em fécula de mandioca (0-3%), quitosana (0-3%), cera de carnaúba (0; 0,2%) e glicerol (0,6%) e suas propriedades de interesse foram determinadas. A incorporação da cera reduziu em média 20% a taxa de permeabilidade ao vapor d’água (TPVA), em relação aos filmes sem cera. Dentre os filmes contendo cera, 1c (3% de fécula) e 2c (2% de fécula e 1% de quitosana) apresentaram valores mais baixos de TPVA, 12,55 g/m²h e 12,42 g/m²h respectivamente, sendo então submetidos a outras caracterizações que revelaram que a substituição parcial da fécula pela quitosana não afetou a espessura dos filmes, causou decréscimo de 14% em sua solubilidade e melhorou suas propriedades mecânicas, o que significa aumento em seu potencial para a aplicação pretendida.