Desenvolvimento e aplicação de filmes de acetato de celulose com nitrito de sódio para manutenção da cor de carnes bovinas

Abstract

The objective of this study was to develop and evaluate cellulose acetate films incorporated with sodium nitrite to maintain the color of vacuum-packaged beef. Initially, the films were produced testing four treatments (1.1%, 2.2%, 3.3%, and 4.4%). The films were applied to vacuum-packaged beef and stored for 20 days at 4 °C. No significant differences were observed in residual nitrite levels in the samples. The controlled release of nitrite from the films promoted a pinkish-red coloration in the samples. Significant increases in a* and C* values and decreases in L* and h* were observed, indicating a more vivid and attractive color in the nitrite-treated meats. Films containing 2.2% (TN1.0) and 4.4% (TN2.0) nitrite were selected for subsequent stages and compared with a control film without nitrite (TAC). Mechanical properties such as thickness (71.97 μm), tensile strength (25.61 MPa), and elongation at break (4.97%) did not differ significantly (P > 0.05). However, puncture resistance increased by 45% in the TN1.0 film. Nitrite migration was higher in TN2.0 (0.24 mg NO2−/cm2). Physicochemical characteristics such as moisture (6.43%), solubility (0.58%), and water vapor permeability (274.05 g/day×m2) showed no significant variations. Film transparency remained high (92.33–92.68%), and scanning electron microscopy revealed that nitrite addition increased the heterogeneity of the polymer matrix. Beef samples were evaluated for up to 56 days at 4 °C, including a control without film (CONT). Nitrite- containing treatments reduced metmyoglobin formation, resulting in a redder, darker, and more intense color (lower h*, lower L*, and higher C* values). No significant change was observed in pH (5.7–5.8), although purge increased over time (P < 0.001). Residual nitrite levels remained below the maximum limit allowed by legislation. TBARS values were lower in nitrite-treated samples, reaching 0.40 mg MDA/kg on day 42. Total volatile basic nitrogen (TVB-N) values increased throughout storage (6.07 mg/100 g by day 56), consistent with microbial growth (5.47 log CFU/g). After package opening and blooming, beef samples showed more intense redness, with increased a*, C*, h*, and b* values over time. In conclusion, cellulose acetate films with sodium nitrite represent a viable and sustainable solution for the meat industry, effectively maintaining color, ensuring food safety, and extending the display life of vacuum-packaged beef. This approach may contribute to product valorization and reduce losses throughout the supply chain.