51A-32

C. Neiva¹, R. BROMBERG¹, L. Miyagusku, and A. M. Pupin. (1) Meat Technology Centre, Institute of Food Technology, Avenida Brasil, 2880, Campinas, 13037-001, Brazil

The consumer demand for fresh, refrigerated foods with extended shelf life has directed researches toward modified atmosphere technology.

The aim of this work was to determine the shelf-life of fresh hake fillets packaged in high barrier film bags stored at 2.5 ± 0.5°C using different gas mixtures compared to 100% air.

Hake fillets were placed on a foam tray containing a soak pad inside a high barrier film bag. The film bags containing fillets were packaged under two gas mixtures (30% O2:40% CO2:30% N2 ; 30% O2:70% CO2) or 100% air. Microbiological, physicochemical and sensory tests were carried out at 0, 2, 5, 7, 9, 12 days. Measurements were taken each time from two samples chosen at random. Microbiological tests: psychrotrophic aerobic colony counts, detection of fecal coliforms, lactic acid bacteria, Pseudomonas, Clostridia SH2+, yeast and molds were carried out. Physicochemical tests: pH measurement, total volatile nitrogen base (TVBN) content and the volume ratio of gas headspace were evaluated. Sensory tests: were assessed visually by 7 trained panelists to identify fillets colour, odour and appearance, according to the quantitave descriptive analysis method (QDA). The SAS system was used to assess the data. Differences between data were assessed using ANOVA and differences in mean scores were compared by the Tukey test (p£0.05).

Hake fillets packaged in 100% air spoiled after 2 days, as indicated by sensory characteristics and had increased surface pH, TVBN content and high microbial counts. When levels of CO2 were increased from 40 to 70% in the package atmosphere, the shelf life was extended 7 days more than that of fillets packaged under 100% air.

Modified atmosphere technology proved to be efficient in extending the shelf life of hake fillets stored at refrigeration temperature.