Abstract:

In order to extend the storage life of fresh mutton, the effect of modified atmosphere packaging (MAP) with
various gas components on the quality of fresh mutton during ice temperature storage was determined. Sensory evaluation
scores, color, drip loss rate, total volatile nitrogen (TVB-N), pH value and microbial loads of mutton samples packaged
in 75% O2 + 25% CO2 and 75% N2 + 25% CO2 atmospheres and stored at ice temperature (-1 ℃) were analyzed. Vacuum
packaging was used as control. The results showed that the drip loss rate of fresh mutton in vacuum package was
significantly higher than that of modified atmosphere packaged mutton, but the color and sensory evaluation of mutton
packaged in 75% N2 + 25% CO2 atmosphere were worst among the three types of packages. Mutton packaged in 75% O2 +
25% CO2 atmosphere had the best color and sensory evaluation scores, lower drip loss rate, and lower pH value. After
42 d storage of the mutton packaged in 75% O2 + 25% CO2 atmosphere at ice temperature, the counts of total bacteria,
Pseudomonas and lactic acid bacteria were 5.91, 5.95 and 5.23 (lg(CFU/g)), respectively, and the total number of bacteria
was not higher than that of first-grade fresh meat according to the national standard of China. In general, 75% O2 + 25%CO2
atmosphere package combined with ice temperature (-1 ℃) can extend the storage life of fresh mutton for as long as 42
days, and this method is suitable for maintaining the quality of fresh mutton during storage.

Key words: mutton, modified atmosphere packaging, ice temperature, storage