Antioxidant Activity of Marjoram Extract and its Effect on the Antioxidative Properties of Broilers’ Chicken Meat

Abstract
 
The antioxidant properties of marjoram ethanolic extract (MEE) were evaluated in the present study. The total antioxidant capacity of the extract was found to be 323.86 mg ascorbic acid equivalent/g, total phenolic content was 177.08 mg gallic acid equivalent/g and total flavonoids content was 54.43 mg querectin equivalent/g. A total number of ninety Ross broiler chicks (one day old)  were distributed into three groups of three replicates each. The chicks were reared for 36 days and the dietary treatments consisted of a corn-soybean meal basal diet (control); the test diet was supplemented with 100 ppm marjoram extract (T1); and the second test diet was supplemented with 500 ppm marjoram extract (T2). At the end of the experimental period, breast and thigh meat samples were separately stored and refrigerated at 4°C. The meat samples were analyzed at three storage periods (day 1, 3, and 7) for their proximate composition and antioxidative activity. The results showed that the supplementation of MEE into broilers’ diet did not have any significant influence on the proximate analysis of breast and thigh meat. On the other hand, the total phenolic content of groups T1 and T2 was significantly (p<0.05) higher than that of the control group. The addition of MEE resulted in a significant ((p<0.05) improvement in the  1,1-Diphenyl - 2 - picrylhydrazy (DPPH) radical - scavenging activity of chicken meat in T1 and T2 as compared to control. The meat samples of T2 retained their high scavenging activity up to storage day 7. Also, the supplementation of diets with MEE caused a significant (p<0.05)  delay in lipid oxidation of chicken meat in T1 and T2 as compared to control. The results of the present work suggest that the dietary inclusion of marjoram extract in broilers diet can improve their antioxidative activity during refrigerated storage.