This study investigated the antimicrobial effects of lactic acid (LA) (3%) and peracetic acid (PA) (300 ppm) on tilapia fillets (Oreochromis niloticus) by fogging (15 min) or by immersion (2 s) in a pool of Escherichia coli (NEWP 0022, ATCC 25922, and a field-isolated strain), Staphylococcus aureus (ATCC 25923 and a field-isolated strain), and Salmonella Typhimurium (ATCC 13311 and ATCC 14028), as well as the effects on the physicochemical characteristics of the fillets. Fogging was effective and the best application method to control S. Typhimurium regardless of the acid used, promoting reductions of 1.66 and 1.23 log CFU/g with PA and LA, respectively. Regarding E. coli, there were significant reductions higher than 1 log CFU/g, regardless of the treatment or acid used. For S. aureus, only immersion in PA showed no significant difference (p < 0.05). For other treatments, significant reductions of 0.98, 1.51, and 1.17 log CFU/g were observed for nebulized PA, immersion, and LA fogging, respectively. Concerning the pH of the samples, neither of the acids used differed from the control. However, treatments with LA, and fogging with PA, reduced the pH compared to immersion in PA. As for color parameters, L* and a* values showed changes regardless of the acid or method used, resulting in an improved perception of fillet quality. These results indicate that fogging and immersion are alternatives for reducing S. Typhimurium, E. coli, and S. aureus in tilapia fillets.

Bio-based materials from proteins, polysaccharides, and lipids have been studied as biodegradable alternatives to synthetic plastics, as well as matrices for incorporation of bioactive substances. In this context, pectin is a polysaccharide used to produce flexible food packaging films. Propolis is a complex mixture of resinous substances with antimicrobial and other biological properties that can be used to generate active food packaging. However, the application of such materials is still limited due to their hydrophilic nature. Thus, this experimentally evaluated the sorption isotherms and isothermal heat of sorption of pectin-propolis films at temperatures of 15, 25, 30, and 35 °C, and determined the mathematical model that best fits the experimental data obtained. The pectin was extracted from pequi mesocarp, a widely consumed fruit in the Brazilian cerrado biome that generates large amounts of peels (exocarp and mesocarp) which are discarded. Among the mathematical models studied, the Sigma Copace model was found to best represent the hygroscopic behavior of the pectin-propolis films. The isothermal heat of sorption decreased with increasing water content, and the films presented similar behavior to agricultural products. The understanding of such film’s behavior contributed to the application of pectin-propolis films produced using pequi mesocarp as a pectin source.

The objective of this work was to prepare a hydrosoluble base extract of baru nut and to evaluate the physical and chemical stability, as well as the content of bioactive compounds. Three formulations with different proportions of baru:mineral water were prepared: 1:6, 1:8 and 1:10. Baru almonds were purchased from the local market in Rio Verde, GO, Brazil. The extracts were prepared with water, centrifuged, pasteurized, packaged and refrigerated at 5ºC. The pH, titratable acidity, colour parameters, antioxidant activity and total phenolic content of all formulations. Satisfactory levels of the bioactive compounds were found in all the proposed formulations of water soluble extract of baru. The 1:6 formulation presented minor changes throughout the ten days of storage. The processing used in this study was useful for obtaining the water soluble extract of baru.