Study On Extraction Methods Of Oil From Pumpkin Seed

This paper study using pumpkin seed as raw materials，discussing the n-pentaneextraction method, aqueous enzymatic method and salt effect auxiliary agent method forextracting pumpkin seed oil. The influence of different extraction conditions were discussedto determine the optimum process parameters extraction, and the physical-chemicalcharacteristic was also analyzed.Main results are as follow:To investigate the feasibility of extraction by n-pentane, pumpkin seeds were used asraw material. Thorough single factor experiment and respond surface methodology, the resultsshowed that the optimal extraction conditions for pumpkin seed oil extraction with n-pentanewere extraction temperature30℃, extraction time5h, extraction time30min andliquid-to-material ratio12, oil yield was50.4%and extraction rate can reach98.8%. Theacid value and peroxide value of the oil were lower than the corresponding value of thenational quality standards. The results showed that pumpkin seed oil extraction by n-pentaneas new solvent was workable.Pumpkin seed oil was extracted by the aqueous enzymatic method, using pumpkin seedand alkaline protease as raw materials, basing on single-factor experiments, effects of enzymedosage, liquid-solid ratio and extraction time on free oil yield of pumpkin seed wereinvestigated and the parameter optimization of the three factors was carried out byBox-Behnken experimental design. The optimum conditions were enzyme dosage1.3%,hydrolysis temperature50℃, liquid-solid ratio7, hydrolysis time2.5h, and oil yield ofpumpkin seeds can reach67.8%. Under the above conditions, the physicochemical propertiesof pumpkin seed oil were lower than the corresponding of the national edible oil qualitystandards, demonstrating that aqueous enzymatic extraction pumpkin seed oil was workable.The oil was extracted from pumpkin seed by the aqueous method with sodiumcarbonate solvent as the extractant which aims to overcome severe emulsification andincreases the oil yield. The sodium carbonate concentration, stirring temperature, liquid-solidratio and extraction time on oil yield of pumpkin seed were investigated and the optimalparameters were carried out by Box-Behnken experimental design. The results showed thatthe concentration of sodium carbonate solvent and liquid-solid ratio had significant effect onthe oil yield. The optimal conditions were sodium carbonate concentration1.8mol/L,liquid-solid ratio6.8, extraction time120.2min, temperature80℃, the oil yield of pumpkin seeds can reach70.8%.The acid value and peroxide value of oil were lower than thecorresponding value of the national quality standards. It demonstrated that technology foraqueous extraction of pumpkin seed oil by salt effect was workable.