Studies On The Preparation Technology Of Extra Virgin Sesame Oil And Sesame Protein

At present,to get nice smell,sesame traditional hot pressing process will do heat treatment on sesame,which will make sesame oil have a lot of carbonyl compounds,thermal polymerization compound,carcinogenic substance(such as benzene and(a)pyrene)and pigment,etc.And the quality of the sesame oil is poor.Due to the high temperature processing,the protein of sesame is badly damaged and the use range of sesame cake reduces a lot,the sesame cake can hardly be used in food.As vegetable oil producing industry develops rapidly,low temperature press technology gradually matures.There have been various brands low temperature press sesame oils,but their production process standard is not clear,their shelf life is short,the conventional Index such as POV and acid value rebounds quickly.So usually factories will fill with nitrogen and add a large number of antioxidants,which will result in an unstable product quality.So it's imperative to find out a safe and reliable method for producing sesame oil.(1)Studies on the preparation technology of extra virgin sesame oilThe nutritional components of 7 kinds of sesame were compared.According oil content,linoleic acid content,linolenic acid content,sterol content of cold pressed oil,vitamin E content as well as the sesame seed price,Ethiopia two grade sesame were used to prepare extra virgin sesame oil.The explored preparation technology of extra virgin sesame oil is as below.The raw sesame oil got from low temperature pressing,is added with compound enzyme solution(Bacillus subtilis protease,Neutral cellulose and neutral pectinase)after filtration and is treated with ultrasonic treatment and stir at the same time.After the enzyme treatment,the raw sesame oil is treated with microwave treatment,then the raw sesame oil is cooled down and stay at the low temperature for a while.After that,the raw sesame oil is leached the second time,then the extra virgin sesame oil is obtained.Single factor and orthogonal experiments are conducted about the main factors of production process of the extra virgin sesame oil and the best level of factors is obtained.It's as below: Enzyme dosage – 1000 u/g,ultrasonic treatment power density-0.5 W/cm2,ultrasonic treatment time-1 h,microwave treatment power – 800 W.The physical and chemical indexes of sesame oil produced by extra virgin sesame oil and ordinary low temperature press technology were detected and analyzed.Results show that acid value,peroxide value,iodine value,saponification value,the content of vitamin E,sterol content of extra virgin sesame oil and sesame oil produced by ordinary low temperature press technology has no significant difference.The induced time of oxidation stability test of extra virgin sesame oil(330 min)is higher by 17% than sesame oil produced by ordinary low temperature press technology.The phospholipid content of extra virgin sesame oil(0.03%)is lower by 70% than sesame oil produced by ordinary low temperature press technology.The acid salt content(0.04%)is lower by 55%.The explored preparation technology of extra virgin sesame oil is as below.The raw sesame oil got from low temperature pressing,is added with compound enzyme solution(Bacillus subtilis protease,Neutral cellulose and neutral pectinase)after filtration and is treated with ultrasonic treatment and stir at the same time.After the enzyme treatment,the raw sesame oil is treated with microwave treatment,then the raw sesame oil is cooled down and stay at the low temperature for a while.After that,the raw sesame oil is leached the second time,then the extra virgin sesame oil is obtained.(2)Studies on preparation technology of sesame proteinSesame cake obtained by extra virgin process is used as raw material.The sesame protein is made from defatted sesame cake(oil content is less than 1%).The explored preparation technology of sesame protein is as below: defatted sesame cake is added with water then the mixture is treated with Homogenate treatment.After that,the mixture is treated with ultrasonic treatment.After the ultrasonic treatment,the mixture is treated with centrifugal separation and the liquid supernatant is obtained.Then pH value of the liquid supernatant adjusted to appropriate value and compound enzyme solution is added to the liquid supernatant.After that,the liquid supernatant is treated with ultrasonic treatment.After the enzyme reaction ended,hydrochloric acid solution is added to the mixture to decrease the pH value to 4.3 so that the sesame protein precipitates.And the mixture with sesame protein is treated with centrifugal separation and the sesame protein is obtained.Then enzyme of sesame protein is inactivated by heat treatment.Then the sesame protein is obtained.Single factor and orthogonal experiment were conducted with the purity of sesame protein as the index.The optimal technology conditions for the preparation of sesame protein were determined as below.Homogenate treatment time is 10 min,ultrasonic treatment time is 1 h,ultrasonic power density when enzymatic treatment is 0.5 W/cm2,enzyme treatment time is 2 h,enzyme dosage is 0.1%.By the best preparation technology,the sesame protein extraction rate is 74.75% and the purity of sesame protein is 89.8%.Amino acid analysis showed that it contained all kinds of amino acids in sesame seeds.The paper is about exploring the preparation process of extra virgin sesame oil and the sesame protein,and reasonable and efficient process steps and process parameters were obtained.The physical and chemical properties of sesame oil and sesame protein were detected.It not only enriched the existing sesame oil variety,but also provided the technical support for the comprehensive utilization of sesame.