The influence of meat storage atmosphere on the quality parameters

This study was carried out to assess the effect of storage conditions on the sensory, quality parameters and microbiological status of beef from the muscle “Semitendinosus”. The experiment was design into 4 groups of beef samples, the first was control and the others were unpacked, aerobic packed and vacuum packed chilled meat. The obtained results showed that the mean values of mesophilic counts were 6×10⁷±5×10⁶, 3×10⁷±3×10⁶, 3×10⁷±2×10⁶ and 5×10⁷±5×10⁶ CFU/g, while those of psychrophilic count were 5×10⁷±5×10⁶, 3×10⁶±3×10⁵, 4×10⁶±3×10⁵ and 7×10⁶±7×10⁵ CFU/g, whereas the mean values of coliforms MPN were 10⁵±10⁴, 10⁵±10⁴, 2×10⁴±10³ and 4×10⁷±2×10⁶ MPN/g, the mean values of fecal coliforms MPN were 2×10³±2×10², 4×10⁴±3×10³, 2×10³±10² and 10⁷±10⁶ MPN/g, the mean values of E. coli MPN were 9×10²±9×10, 6×10±6×10², 6×10³±10² and 2×10³±10² MPN/g and the mean values of Staphylococcus count were (9×10⁵±9×10⁴, 10⁶±10⁵, 2×10⁶±10⁵ and 2×10⁶±2×10⁵ CFU/g) for control, unpacked, aerobic packed and vacuum packed chilled stored beef, respectively. The unpacked meat showed increase in shelf life time till four days as the sensory evaluation become excellent till four days also, increased pH, drip, water holding capacity (WHC) and cooking loss at four days. Staphylococcus reach to unsatisfactory level. Area packed meat increase in shelf life time till six days showing excellent sensory evalution at six day, decreasd drip, water holding capacity and cooking loss and slowly increased in bacterial count. Anaerobic meat have the longest shelf life time till 10 days as vacuum packing reduce drip, WHC and cooking loss. Also decrease mesophilic, fecal coliform growth. The quality assurance of cold storage was discussed as well as the vacuum packaged chilled beef has long shelf –life time than aerobic packed and fresh meat. This attributed to that package and cold storage reduce microbiological and physio-chemical alterations in meat. The recommendations to extension of shelf life time were discussed.