Dietary tea catechins and iron-induced lipid oxidation in chicken meat, liver and heart.

The effects of dietary tea catechins (TC) supplementation at levels of 50 (TC 50), 100 (TC 100), 200 (TC 200), and 300 (TC 300) mg kg(-1) feed on susceptibility of chicken breast meat, thigh meat, liver and heart to iron-induced lipid oxidation were investigated. Day old chicks (n=200) were randomly divided into six groups. Chicks were fed diets containing either basal (C), or α-tocopheryl acetate supplementation at a level of 200 mg kg(-1) feed (VE 200), or TC supplementation for 6 weeks prior to slaughter. Lipid oxidation was assessed by monitoring malondialdehyde formation with 2-thiobarbituric acid (TBA) assay. TC supplementation at all levels exerted antioxidative effects for all tissues with the exception of 50 mg kg(-1) feed for breast meat. TC supplementation at levels of 200 and 300 mg kg(-1) feed were found to be significantly (P<0.05) more effective in retarding lipid oxidation in all tissues, compared to the control. TC supplementation at a level of 300 mg kg(-1) feed was also found to be significantly (P<0.05) superior to vitamin E supplementation at a level of 200 mg kg(-1) feed (VE 200) for oxidative stability in chicken thigh meat, but it was inferior to VE 200 in chicken liver and heart. TC supplementation at a level of 50 mg kg(-1) feed was found to be pro-oxidative in breast meat, but this did not occur in chicken thigh meat, liver and heart. The variation of TC antioxidative properties in different tissues may be explained by the uneven distribution of lipid, iron and TC accumulation in tissues.