Colour stability and lipid oxidation of fresh beef. Development of a response surface model for predicting the effects of temperature, storage time, and modified atmosphere composition.

Samples of fresh beef muscles (Longissimus dorsi) were packed under varying modified atmosphere conditions (20-80% oxygen) and stored at 2-8°C for 10 days. At 2 day intervals meat samples were analysed for surface colour and extent of lipid oxidation (TBARS). Response surface models for predicting the effects of temperature, storage time and modified atmosphere composition on colour stability and lipid oxidation were developed. Temperature and time were found to be the most important factors for retaining meat colour and minimizing lipid oxidation. However, the oxygen content also had a significant effect on both quality parameters. A stable interval of maintaining a good meat colour was found between 55 and 80% O(2). Response surface modelling was found to be very promising for modelling of chemical quality changes in meat stored under different conditions, but the large biological differences between animals may complicate the development of generally valid models.