Study On The Subcritical Extraction Of Cottonseed Oil And Purification The Protein By Reverse Micelles

The annual output of cottonseed reached over10million tons in China, which is an importantresource of plant oil and protein. Now producers put empHasis on high level of oil yield, and ignore thequality of the cottonseed cake with plenty of protein. The high processing temperature and pressure,mechanical forces cause denaturation of the protein, and part of the amino acids reacts with othersubstances in the cottonseed cake, reducing the effective use composition of cotton seed protein. All ofthese are not conducive to further purification of cotton seed protein, resulting in huge waste. So how tomake a way of low temperature extraction process for cottonseed, not only to ensure the oil yield, butalso to avoid protein denaturation is the research direction and focus in future. In this study, we gotcottonseed oil using subcritical extraction technology, and further purification of cottonseed proteinbased on reverse micelle purified technology.1）Through the comparative analysis of pHysical property, security and energy consumption ofpropane, butane, tetrafluoroethane, we chose n-butane (purity>99.9%) as subcritical extraction solventfor cottonseed oil. Single factor test and Box-Benhnken central composite response surface analysiswere employed to optimized the subcritical extraction system, and the optimal parameters are asfollows: temperature46.6℃, extraction time36.3min, extracted times4, sample treatment of seedscrushed after60mesh flaking. After measurement, the extraction rate can be achieved94.02%ofcottonseed oil under this condition.2） The gas chromatograpH-mass spectrometer (GC-MS) and high performance liquidchromatograpH (HPLC) were employed to identify the quality of cottonseed oil and meal after thesubcritical extraction. The results showed that the quality of cottonseed oil significantly superior to thequality requirements specified in the national standard, and most indicators have reached or exceededthe level of finished product. The cottonseed meal is light yellowish white, and protein content reach upto62%with no degeneration occurs. However, it has provided a further processing and utilization valuefor food, medicine and feed industry.3） Further purified of cottonseed meal by reverse micelles subcritical extraction, we haddetermined the anionic AOT/SDS reverse micelle solution as extracting solution. Single factor andorthogonal test results showed that: the system of AOT concentration0.08g/mL, SDS concentration0.06g/mL, buffer amount of2.4mL, solvent and co-solvent ratio is4/1, and the value of Solubilizingwater（Wo）reached the maximum.4）Focusing on the process of forward and backward extraction process of complex reversemicelle system, based on quadratic general rotatable design and orthogonal experiment design, weobtained the optimum conditions for forward extraction:Solubilizing water Wo=15.8, pH=7.7, KClconcentration of0.051mol/L, the extraction temperature is40℃, extraction time was60min,solid-liquid ratio of0.015g/ml, and at this time the extraction rate was85%. Moreover, the optimumconditions for backward extraction: pH=8, KCl concentration of1.2mol/L, extraction temperature is40℃, extraction time90min, and at this time the extraction rate was75.1%. Finally, the cottonseed protein extraction rate was63.7%，and the puriiy of protein over90%.5）Through protein chemical composition, quality analysis and some other restrictive factors ofextracted protein, we found abundant amino acids and total content of eight essential amino acids inhuman body, reaching more than30%，the limiting factor gossypol of purified protein is far belowcurrent safety standards. we made some comparison to alkali extraction and acid precipitation, Enzymichydrolysis，found that the cost and extraction effect of Method combined with subcritical extraction andpurification ofreverse micelles is better than the first two.