The results have shown that the method had provided highest extraction yield, but the oil had been the most oxidized. Meanwhile, the mechanical method provided lower extraction yield, but the quality of the product was much more better, met the requirements of commercial fish oil product. The addition of ginger and tea extract to fish suspension before extraction lowered the peroxide value of extracted fish oil significantly. | TẠP CHÍ KHOA HỌC VÀ CÔNG NGHỆ Tập 48, số 5, 2010 Tr. 113-121 THE OXIDATION OF FISH OIL DURING EXTRACTION PROCESS AND STORAGE ĐẶNG MINH NHẬT, LÊ VĂN HOÀNG ABSTRACT Fish oil has high nutritional value, but easily undergoes oxidation to form many undesirable products. The aim of our study was to evaluate the effect of fish oil extraction methods on the extraction yield and the oxidation state of the product. Besides, the effect of natural and synthetic antioxidants on the quality of fish oil during extraction and storage were also examined. Extraction methods selected in this study included: method, Soxhlet method and mechanical methods with and without addition of ginger and tea extract. The oxidation of extracted fish oil was evaluated by peroxide value (PV). The results have shown that the method had provided highest extraction yield, but the oil had been the most oxidized. Meanwhile, the mechanical method provided lower extraction yield, but the quality of the product was much more better, met the requirements of commercial fish oil product. The addition of ginger and tea extract to fish suspension before extraction lowered the peroxide value of extracted fish oil significantly. The presence of ginger and tea extract in fish oil also retarded the oxidation, this effect was as high as the effect of the popular synthetic antioxidant BHT. 1. INTRODUCTION It has been well documented that fish oil possesses many health benefits. Fish oil provides source of important ω-3 fatty acids whose effects on human have been widely studied. The results from many works have shown that ω-3 fatty acids lower the level of triglyceride in blood, antiarthritic, improve memory and ability to concentrate. ω-3-fatty acids also prevent cancer, improve vision, lower blood pressure and more other medical benefits. That explains why fish oil is an important product in world trade. The fatty acid composition of fish oil is completely different from those of land .
