Oxidation Control Technology Of Peanut Oil During Processing And Storage

First, oxidation control problems of pressing peanut oil during baking and cooking process were studied. Results showed that oxidation stability of peanut oil was influenced by temperature and time. High temperature and long time resulted in serious oxidation while baking. Also, appropriate temperature and time during the processing of cooking could control the oxidation and obtain high yield of oil. Experiments were focused on whole peanuts. It illustrated that whole peanuts were able to form better flavor and lustrous than those of broken ones. It was found that temperature of 180℃and time of 20min was suitable for baking whole peanuts, and 110℃and 50min was suitable to cooking broken ones.Second, removing process of phosphatide and other colloid was studied. Sodium chloride, citric acid and trisodium citrate were used for degumming. Results illustrated that citric acid achieved a maximum effect. Other conditions such as temperature and time were also studied. The optimum process was that after suction filtration of crude oil, weighed it and heated to 75℃,added citric acid solution into it (1mL citric acid solution with the concentration of 8% added into 100g oil), mixed rapidly for 5min, quickly heated to 80℃, kept at a uniform temperature for 20min, centrifuged for 20min and filtered to obtain oil with ideal degumming effect.At last, oxidation control technology of peanut oil during storage process was studied. New edible oil container was designed, based on the principle that oil could remain edible and long-term storage after opening because oil was able to fill the package at any time in use and then discharge the air inside the package effectively. There were three design proposals, which were channel-type opening, piston-type opening and ball-type opening together with composite materials which volume was variable. The anti-oxidation ability of different composite materials was explored and the feasible one was applied to oil packaging system. Meantime, fresh-keeping effects were evaluated through experiments, which demonstrated that the new package had good effect for fresh-storage of peanut oil, sunflower seed oil and tea seed oil. Measurement and analysis of fatty acid composition and vitamin E of oil showed that new package and bottled package produced no significant impact to fatty acid composition. There was no significant difference between the new package and bottled ones in the aspect of vitamin E content in peanut oil while a little decline, but the content declined obviously in bottled sunflower seed oil and tea seed oil and new-packaged oil showed no apparent change,which further explained that the new package had better influence for fresh-storage of edible oils.