Research On The Refining Process Of Corn Oil And Process Design

Corn is an important oil crop, corn oil is rich in many physiologically active componentssuch as unsaturated fatty acids and tocopherols, sterols and other essential nutrients. Corn oilnot only has good natural antioxidation and stability, has high nutritional value because of theexisting of tocopherols and sterols. However, the refining process will cause large loss oftocopherols and sterols. Meanwhile, the tocopherols and sterols are lost during storage. It isnecessary to further research the change of total tocopherols and single tocopherol duringrefining and storage so that we can produce high quality corn oil.The change of total tocopherols content and single tocopherol content were researchedduring refining, the results showed that during refining process, the loss of four singletocopherol was different, comparing to other tocopherols, the α-tocopherol, β-tocopherollost more than other tocopherols, the highest being36%,41%. The alkali dosing amount,alkali refining temperature, alkali concentration were researched by single factor test andorthogonal test, the effects of the variables on the tocopherols content decreased in the order:the alkali dosing amount＞alkali refining temperature＞alkali concentration. The optimumconditions of the refining were alkali dosing amount0.2%, alkali concentration12oBe, alkalirefining temperature70℃.The change of total tocopherols content and single tocopherol content were researchedduring bleaching, the results showed that during the bleaching process, the loss of four singletocopherol was different, comparing to other tocopherols, the α-tocopherol lost more thanother tocopherols, the highest being59%. The bleaching temperature, bleaching time,decolorization clay dosage were researched by single factor test and orthogonal test, theeffects of the variables on the tocopherols content decreased in the order：bleaching time＞decolorization clay dosage＞bleaching temperature. The optimum conditions of the bleachingwere temperature105℃, bleaching time20min, decolorization clay dosage2.5%.The change of total tocopherols content and single tocopherol content were researched during deodorization, the results showed that during the deodorization process, the loss offour single tocopherol was different, comparing to other tocopherols, the γ-tocopherol lostmore than other tocopherols, the highest being56.7%. The deodorization temperature,deodorization time were researched by single factor test and orthogonal test, the effects of thevariables on the tocopherols content decreased in the order: deodorization temperature＞deodorization time. The optimum conditions of the deodorization were deodorizationtemperature220℃, deodorization time100min.After30days storage, the loss of tocopherols content under sealing and openingcondition was slightly on same temperature. During storage period, δ-tocopherol lostminimum and the loss changed slightly. The tocopherols decreased in the order α-tocopherol,β-tocopherol,γ-tocopherol,δ-tocopherol under different storage conditions.