Differences in meat colour between free-range Swallow Belly Mangalitsa and commercially reared Swedish Landrace pigs during 6 days of vacuum storage

The influence of storage on meat colour differences between free-range Swallow Belly Mangalitsa (MA, n = 19) and commercially reared Swedish Landrace (SL, n = 17) pigs, are investigated in the present study. Proximate composition analyses were done on fresh samples of M. longissimus thoracis (LT) and M. gluteus medius (GM), while pH values and colour quality attributes were determined on fresh cuts of the muscles (day 1) and after 3 and 6 days of vacuum storage at 4 +/- 1 degrees C. MA pork had a significantly higher share of intramuscular fat, a darker colour, a higher deoxymyoglobin (Mb) content and oxy / met (oxymyoglobin / metmyoglobin) ratio, higher pH(24h) values and a slower pH decline compared to the control SL group (P < 0.05). Greater changes in myoglobin forms during storage were observed in MA pork, which were reflected in a significant decrease in the content of Mb and an increase in the oxy / met ratio (P < 0.05). After 6 days of vacuum storage, higher pH(6d) values, a lower metmyoglobin (MetMb) content and a higher oxy / met ratio of MA pork lead to the conclusion that aged meat from free-range Swallow Belly Mangalitsa pigs had better colour quality compared to Swedish Landrace pigs.