Biogenic amine formation in turkey meat under modified atmosphere packaging with extended shelf life: Index of freshness.

The aim of this study was to evaluate the effect of modified atmosphere packaging (MAP) on biogenic amine production in turkey meat according to its shelf life period, determining an index of freshness. Sliced meat samples of different meat quality categories (according to color and pH₂₄) were individually packaged under aerobiosis (aerobic package) and in 6 different modified atmospheres containing different gas mixtures: MAP1, 50% N₂/50% CO₂; MAP2, 0.5% CO/50% CO₂/49.5% N₂; MAP3, 50% Ar/50% N₂; MAP4, 0.5% CO/80% CO₂/19.5% N₂; MAP5, 100% N₂; and MAP6, 50% Ar/50% CO₂. All samples were stored at 0 ± 1°C in the dark for between 12 and 25 d. Meat samples packaged in aerobic packaging were analyzed for their microbial and physicochemical characteristics on d 0, 5, and 12 of storage, and then extended to 19 and 25 d when samples were under MAP. The production of biogenic amines analyzed in turkey meat increased over time. The values of putrescine, cadaverine, and tyramine increased significantly (P < 0.05) during storage time in samples packaged under aerobiosis, MAP3, and MAP5. Histamine was not detected in turkey meat packaged under study conditions, or when present, the levels were below the limit of quantification (1.03 mg/kg). Tyramine in turkey meat under MAP was not the best amine indicator of meat deterioration, with cadaverine being suggested instead, or the sum of the amines putrescine, cadaverine, and tyramine, to characterize and quantify meat freshness. After 25 d of storage, the meat packaged under MAP with a mixture containing a higher concentration of CO₂ and with CO was the one with a lower index value (11.36 mg/kg), although not significantly different from the indices provided by the meat packaged with MAP1, 2, and 6.