Dietary tannins improve lamb meat colour stability

Fourteen male Comisana lambs were divided into two groups at 45 days of age: lambs fed a concentrate diet (C), or lambs fed the same concentrate with the addition of quebracho (Schinopsis lorentzii) tannins (T). Sheep were slaughtered at 105 days of age. Lipid oxidation, colour coordinates, haem pigment concentration, and metmyoglobin percentages were measured on minced semimembranosus muscle (SM) over 14 days of refrigerated storage in a high oxygen modified atmosphere. Tannin supplementation increased (P < 0.01) a∗ values and reduced (P < 0.01) b∗ values of the SM when compared to C. Lower hue angles (P < 0.001) and metmyoglobin formation (P = 0.07) were observed in lamb from T-fed compared to C-fed sheep during the 14-days storage period. Furthermore, feeding T resulted in greater (P < 0.001) haem pigment concentrations in the SM during refrigerated storage; however, diet had no (P = 0.28) effect on lipid oxidation. Therefore, including quebracho tannins in sheep diets can improve meat colour stability of fresh lamb during extended refrigerated storage.