Nix Colour Sensor as potential tool for evaluating colour in rabbit meat

The present study aimed to test an innovative sensor for the instrumental evaluation of colour in rabbit meat. Once the anatomical part representative of the carcass and likely having different energetic metabolism were identified (i.e., loin and hind leg meat), these were stored up to 12 days and used to measure colour by using a tristimulus colorimeter and a colour sensor, a less expensive and user-friendly device. For this purpose, 36 rabbit carcasses (Martini group hybrid, 11-week-old, average live wt 2.7 kg) were considered and dissected to obtain the main muscles used to measure pH 24 h post-mortem (pHu). Then, 15 loins and hind legs were selected, packed in ordinary atmosphere, and stored for 12 days at 4°C. Data concerning pHu were analysed by one-way ANOVA, while colour data obtained throughout storage period were analysed by repeated measures ANOVA. When significant, means were separated by Tukey-HSD (p<0.05). The lowest pHu values were measured in the Longissimus thoracis et lumborum muscle, with special reference to the median and posterior part. These can be attributed to a higher proportion of type IIB fibers with glycolytic metabolism. Different colour values were found when comparing the data obtained with tristimulus colorimeter and colour sensor. These may be due to the light emitting source which is included in the devices ultimately leading to a different scattering of the incident light as a result of its interaction with the meat surface and/or structure. In conclusion, these results indicated that the Nix colour sensor can be a viable alternative to conventional chroma meters for both research and industrial purposes. In addition, updated reference values for pHu for the main muscles of rabbit carcass were provided.