A study on chemical characteristics and antioxidant capacity of pomegranate seed and some herbal pomace against thermal peroxidation of soybean oil during feed processing

The study was carried out to evaluate the polyphenol content, chemical composition, radical scavenging activity and inhibition potential of peroxidation of pomegranate seed and other agricultural by-products such as tomato, apple, lemon and orange pomace in comparison with alfalfa, ascorbic acid, alpha-tocopherol and butylated hydroxyl toluene (BHT) as common antioxidant source of diet. Effect of temperature and duration of oxidation on peroxide value of raw soybean oil were investigated as food processing simulation. The results indicated that peroxide value of soybean oil samples increased by rising temperature and time of oxidation significantly. Total saturated and unsaturated fatty acid contents of oil significantly increased and decreased by oxidation, respectively. The pomegranate seeds methanolic extract had the highest values of polyphenol, radical scavenging activity and inhibition potential of peroxidation among all investigated materials. Pomegranate seeds had notably high fiber, CP, EE, Cu, and Zn content and acidifying potential compared with other investigated by-products. Therefore, pomegranate seed seems to be effective antioxidant and beneficial supplement for peri-parturation period from metabolic point of view.