Study On Extraction And Antioxidation Of Apple Seed Oil

The apple output in China occupies the first place in the world. With the growth of concentrated juice production, amounts of apple residues are produced, causing environmental pollution and resource wasting. With 27.7% of oil content, which contains 89.33% of unsaturated fatty acid, apple seed is a good kind of oil resources. So making use of apple seed oil is another direction of pomace utilization with great economic and social benefits. Apple (Fuji) seed oil was extracted by three methods of organic solvent extraction, ultrasonic-assited extraction, and supercritical carbon dioxide extraction. The yield, properties, fatty acid compositions and the antioxidant capacity of apple seed oil were studied in this thesis.1. Extraction, properties, and fatty acid compositions of apple seed oil. Apple seed oil was extracted after being dried in the shade and pretreatment of comminution degree 60, water content 6%, and steamed time 40min. The yield of apple seed oil was 20.35% being extracted for 6.05h at temperature 32.14℃with the ratio of 7.70:1(v/w, petroleum ether to apple seed). When adopting supercritical carbon dioxide under the pressure of 29.77 MPa for 89.40 minutes at temperature 35.42℃, the highest extraction efficiency could be 22.96%. Moreover, the yield was up to 24.39% by using ultrasonic wave for 33.26 minutes, power of 162.09W with the ratio of 8.28:1(v/w, petroleum ether to apple seed).Apple seed oil belonged to semi-dry oil with iodine value of 114.39 ~ 118.63 g /100g, and needed further refining processing because of its high level of water content and free fatty acids. The gas chromatography-mass spectrum analysis showed that apple seed oil contained palmitic acid, stearic acid, oleic acid, linoleic acid, eicosenoic acid, eicosatrienoic acid, and docosanoic acid mainly. The unsaturated fatty acid occupied 85.60% to 86.96%, especially for polyunsaturated fatty acids (50% of linoleic acid).2. Refining of apple seed oil. The quality indexes of apple seed oil, including phospholipid, saponifiable content, acid value, water content, color and flavor, have met the qualification of hygienic standards for edible vegetable oil after hydrated degumming, deacidification with alkali, washing and drying. The optimum degumming parameters of water addition, hydration temperature, and time were 3%, 70℃, and 30min respectively. And the optimal alkali refining parameters of sodium hydroxide, initial temperature, exceed alkali quantity were 13%, 45℃, and 0.3% respectively.3. Antioxidation of apple seed oil. Subacute aging-mice model was made by intraperitoneal injection of D-galactose(5%) continually. The contents of malondialdehyde(MDA) and the activities of superoxide dismutase(SOD), glutathione peroxidase(GSH-PX) in serum and liver were detected. Compared with the control, content of MDA in the model group significantly increased, and the activities of SOD, GSH-Px decreased; apple seed oil in different doses evidently reduced the level of MDA, increased the activities of SOD and GSH-Px in both serum and liver. Apple seed oil can obviously increase the antioxidant ability of aged mice, and has effects on anti-aging.