The Control Technology Of Oxidation Stability Of Peanut Oil

Firstly, the antioxidant effect of three natural antioxidants on peanut oil were studied. Vitamin E,soybean phospholipids,two different forms of rosemary extracts were chosed to study.Results showed that soybean phospholipids and rosemary extracts exhibited different antioxidative activities on peanut oil, and the0.10%soybean phospholipids and0.07%powdered rosemary extracts are the best. Vitamin E promoted the oxidation of peanut oil when adding excess vitamin E.And compared with the antioxidation of the compound antioxidants of soybean phospholipids and gallicacid, the antioxidation of the compound antioxidants of0.07%rosemary extracts and0.04%gallic acid was the best.Then, the products on the process of pressing peanut oil were collected and analyzed. And the process of removing phosphatide and other colloid was studied. Results illustrated that peanut oil was easily oxidized during baking and cooking process, and oxidation stability of peanut oil was influenced by temperature, dosage of dephosphorization agent and the mixing time. The optimum process was that after suction filtration of crude oil, added3%o citric acid solution what’s concentration is26%into oil, mixed20min at80℃, then centrifuged for20min to obtain oil with ideal degumming effect, and the oxidation stability of the oil had be improved. The experiment confirmed that the crude oil can be stored as a reserved oil.At last, three methods of removing peroxides from peanut oil were studied.First, according to the principles of oxidation and reduction,two reducing agentswere used to reduce peroxides.Results showed that a small amount of cysteine could reduce per-oxides, and reduce the content of peroxides in peanut oil.Thesecond method is preve-nting oils from contacting with oxygen to accelerate theperoxide degradation. Results confirmed that placing the peanut oil at a certain temperature, the contents of peroxi-des in peanut oil could be decreased to a lower level in the conditions of air isolati-on. And the higher the temperature, the faster the rate of degradation of peroxides. Last,the effect of vacuum instan-taneous ultra high temperature method on removing peroxides fromoils.The best combination of molecular distillation was that the distilla-tion temperature,220℃; the system pressure,3-9Pa; the coating speed,200r/min;und-er which,the peroxides in peanut oil could be remove efficiently,the contents of pero-xides in oil could be decreased to a lower level, the fatty acid composition was not destroyed, but the contents of vitamin E could decrease.