Shelf life of fresh foal meat under MAP, overwrap and vacuum packaging conditions

摘要

The objective of this study was to investigate the physico-chemical properties, the microbial counts and the sensory properties' changes of foal steaks packed under various conditions. The experimental packaging systems were: (i) vacuum packaging (VP), (ii) overwrap packaging and (iii) two modified atmosphere packaging methods (MAP): high O_2 MAP (80% O_2 + 20% CO_2) and low O_2 MAP (30% O_2 + 70% CO_2). The meat was stored at 2 ℃ during 14 days and tested for pH, colour, lipid and protein oxidation, microbial counts and sensory assessment of odour, colour and appearance. Of the two MAP, overwrap and VP, both MAP were the most effective treatments for the inhibition of the total viable counts (TVC), Pseudomonas spp., psychrotrophic aerobic bacteria, lactic acid bacteria, Enterobacteriaceae as well as moulds and yeast. According to the sensory evaluation, foal steaks packed under overwrap and MAP treatments resulted unacceptable after 7 days of storage, whereas the vacuum-packed meat was still acceptable. Moreover, the redness value decreased significantly (P< 0.001) with all treatments during the storage time, except for the vacuum packs, which increased significantly (P<0.001). Finally, foal steaks from overwrap packaging and MAP conditions had a greater increase of TBAR'S values and car-bonyl content during the storage time. High O_2 levels affected foal meat quality negatively, while anaerobic conditions extended the meat's shelf life up to 14 days.