Optimization Of The Extraction Parameters And Composition Analysis Of Oil And Polysaccharide From Abelmoschus Esculentus (L.)

Okra pods are commonly used in Asia as a vegetable, food ingredient, aswell as a traditional medicine for many different purposes. Theoptimization of extraction of oil and polysaccharide from okra seeds andpods and the analysis of fatty acid composition of the okra seed oil werestudied in the paper.Soxhlet extraction of oil from the seed of okra Abelmoschusesculentus （L.） was performed in the present research. In this experiment,three single-factor including extraction time, liquid/solid ratio, andtemperature were chosen, and the yield of oil from okra pods wasconsidered as evaluation index.According to single factor experimentalresults, three levels of these three single factors were determined.3factors, 3-level Box-Behnken experimental design was chosen, then quadraticpolynomial regression equation was established and analyzed by responsesurface methodology.the optimum extraction conditions were obtained asfollows: extraction time144.4min, liquid/solid ratio7.4:1, andtemperature65.3℃.Under these conditions, the estimated values ofmaximal yield of oil were15.72%. Fatty acid composition of okra oilobtained was analyzed by GC and GC/MS.The results indicated that theokra seed oil was rich in unsaturated fatty acids which accounted for63.39%of the total fatty acids. The main unsaturated fatty acids arePalmitic acid （29.86%）, stearic acid （3.73%）, oleic acid（24.07%）, linoleicacid（38.22%）, linolenic acid （1.34%）.Monounsaturated fatty acids andpolyunsaturated fatty acids reach25.75%,37.46%, respectively.Supercritical CO₂fluid extraction of oil from the seed of okra wasperformed in the present research. In this experiment, four single-factorincluding carbon dioxide flow rate, extraction time, extraction pressureand extraction temperature were chosen, and the yield of oil from okrapods was considered as evaluation index.According to single factor experimental results, three levels of these four single factors weredetermined.4factors,3-level Box-Behnken experimental design waschosen, then quadratic polynomial regression equation was establishedand analyzed by response surface methodology.the optimum extractionconditions were obtained as follows: carbon dioxide flow rate14.9L/h,extraction time93.9min, extraction pressure299bar and extractiontemperature40.7℃. Under these conditions, the estimated values ofmaximal yield of oil were17.16%. Fatty acid composition of okra oilobtained was analyzed by GC and GC/MS. The results indicated that theokra seed oil was rich in unsaturated fatty acids which accounted for63.53%of the total fatty acids. The main unsaturated fatty acids arePalmitic acid （28.98%）, stearic acid （4.14%）, oleic acid （24.38%）, linoleicacid （38.35%）, linolenic acid （0.35%）. Monounsaturated fatty acids andpolyunsaturated fatty acids reach24.82%,38.71%respectively.In this experiment, four single-factor including extraction time,liquid/solid ratio, temperature and power rating were chosen, andthe yield of polysaccharides from okra pods was considered as evaluation index. According to single factor experimental result,three levels of these four single factors were determined.4-factors,3-level Box-Behnken experimental design was chosen, thenquadratic polynomial regression equation was established andanalyzed by response surface methodology.the optimum extractionconditions were obtained as follows: extraction time113min,liquid/solid ratio41.3:1, temperature61.5℃and power rating72.3W. Under these conditions, the estimated and observed valuesof maximal yield of polysaccharides were2.85%and2.84%,respectively. The experiments provide a reference for extraction ofokra polysaccharides, and lay a foundation for future research ofokra polysaccharides.