Antioxidant Activity of Papaya Fruit Peels in Camel Meat

Lipid oxidation is among factors contributing to quality deterioration of camel meat. Phytochemicals from natural resources are potential quality preservatives. Papaya fruit peel extracts (PE) had a total phenolics of 30.03 mg gallic acid equivalent per gram of dried peels. PE demonstrated both ferric reducing power and radical scavenging activity (RSA). The RSA of PE was 75.65%±2.29 as measured by 2,2-diphenyl-1-picrylhydrazyl protocol. Ferric reducing power increased (r² 0.755) as PE concentrations rose from 1,000 to 6,000 μg/mL. A marinade made from 0.0625% acetic acid, 0.625% gum Arabic, and 900 ppm PE was evaluated for its effects on pH, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen (TVBN), and color profile of camel meat stored at 8±1°C for 12 d. The pH was initially (zero time) reduced from 6.07 (control) to 5.73 in marinated camel meat prior to storage. Marinated camel meat had the lowest TBARS (0.07 mg malondialdehyde, MDA/kg) >6-d storage. Marinades with and without PE exhibited TVBN below <25 mg/100 g, indicating better spoilage control in camel meat stored for 3 d. Camel meat CIE a* (14.22) of PE-treated marinades was not significantly (p<0.05) different than the control (CIE a*=15.12) after 9 d of storage. Marinades with and without PE controlled aerobic bacterial counts in camel meat (<6-d storage) below the European Union limit (<Log 6 colony forming unit, CFU/g) for red meat. Papaya fruit peels are promising sources of natural antioxidants for camel meat. This study is the first on PE and quality of camel meat.