Melanin content and its correlation with weight and color of black-meat chickens at different ages

Abstract

In Asia, black-meat chicken is popular and generally chosen and cooked as functional food because of antioxidant, immunomodulatory, and other anti-aging properties of melanin pigments in various tissues. In the present study, the melanin content was determined in the black-meat chickens in Thailand which consisted of KU-Phuphan (KU), Mongolia (MG) and Phetchabun (PB) breeds. In addition, the correlation between melanin content and weight, color of the breast, drumstick, wing and skin of black-meat chickens at different ages was estimated. The chickens used in the study had hatched at similar times and were raised under comparable management and care conditions. When the chickens were aged 30 d, 60 d, 90 d and 120 d, five chickens from each breed group were randomly collected and slaughtered and their weights and lightness (L*), redness (a*) and yellowness (b*) of the meat were measured. Melanin was extracted from breast, drumstick, wing and skin samples, and measured using an absorption spectroscopy technique. Data analysis was done using a linear model that considered breed, age and interaction between breed and age as fixed factors. Means were computed and then they were compared using t-test. Pearson’s product-moment correlation coefficients (r) between the considered traits were estimated. The average melanin content of all chickens was 0.053 ± 0.031 mg/g and the range was from 0.048 ± 0.041 mg/g (wing) to 0.060 ± 0.041 mg/g (breast). MG chickens tended to have higher weights than KU and PB at all ages. The melanin content increased in PB chickens but decreased in KU and MG chickens between ages 30 d and 120 d. The melanin content was correlated (p < 0.01) with L* (r = -0.330) and b* (r = -0.368), but not with a* and weights. Slaughtering black-meat chickens at age 30 d produced the highest melanin content.