Different technologies have been evaluated to promote food safety and improve the microbiological quality and shelf life of food. The aim of this work was to determine the effect of gaseous ozone on beef carcass weight loss and indicator microorganism counts in an exporting abattoir. Two gaseous ozone concentrations (3 and 10 ppm) were applied on carcasses from Experiment 1 (Exp. 1, n = 100 test, n = 100 control) and Experiment 2 (Exp. 2, n = 100 test, n = 100 control), respectively. Cold chamber without ozone was used as control in both experiments. For mesophilic aerobic organism (MAO), coliform and Escherichia coli counts, 100 cm² of each carcass was swabbed before and 10, 20 and 30 h after ozone application. In Exp. 1, the carcass entire surface was swabbed for Shiga-toxin (stx) gene detection. The counts of MAO were influenced by treatment and sampling time in both experiments. In Exp. 1, control carcasses had higher counts than ozonated carcasses at all sampling times, whereas the opposite occurred in Exp. 2. Coliform count was affected by sampling time in Exp. 2, whereas E. coli count was not affected in any experiment. All samples analyzed were stx-negative. Differences in carcass weight loss were not significant. In conclusion, gaseous ozone was not effective to reduce bacterial load or carcass weight loss. To our knowledge, this is the first study evaluating ozone effect on beef carcasses conducted in a commercial abattoir, not at laboratory scale. Future research would help demonstrate whether the use of ozone impacts on the quality and sensory characteristics of beef.

Preserving minimally processed fruits represents a technological challenge. Therefore, non-thermal plasma (NTP) is proposed as one of the preservation methods. The aim of this work was to evaluate the effect of the application of NTP before and after packaging sliced apples in two films: One with high and another with low oxygen barrier features. Different parameters were evaluated during 14 days at 4 °C. Samples treated before packaging showed lower crunchiness and browning development, as indicated by chromatic and textural parameters. NTP reduced mesophiles, psychrotrophs, and yeasts and molds on the slices by 1–2 log units, although it had no effect on the antioxidant content of the apple slices, which were better preserved with high-barrier packaging. Samples treated with NTP, and low barrier packaging showed lower sugar content on day one. When applied after packaging, NTP contributed to better preservation of slice microstructure and tissue viability. Results showed that the combination of NTP applied after packaging and high-barrier film was the most suitable for maintaining fruit quality, mainly by better preserving slice color. In turn, tissue microstructure, texture analysis, and viability tests also supported this conclusion.