Study On Extraction By High Intensity Pulsed Electric Fields

Recently, non-thermal pasteurization of liquid stuff by using a high intensitypulsed electric fields (PEF) is a new technology. High intensity pulsed electricfields have the merits of uniformity in conducting heat, short processing time, lowenergy consumption and low quantity of heat. The technology of PEF is one of theprimary non-thermal pasteurizations. At present, the research in applying highintensity pulsed electric fields is mostly on food pasteurization, which has got somevery good effects in pasteurization.This paper, combining the development of the PEF, manufactured a highintensity pulsed electric fields, and changed the technical parameters of the PEFsetting with the pasteurization mechanism by PEF, to selectively induce apoptosisof the K562leukemia cells and lymphocyte cells. Soybean of Northeast was usedas the main raw materials for lixiviating and extracting experiments of soybean oil,as a means to advanced high intensity pulsed electric fields, to test high intensitypulsed electric fields and to determine the related parameters. In order to providethe technology support of the pomace integrated utilization and pectin extraction,the research focused on the key problems of pectin extraction.Through extraction by high intensity pulsed electric fields, we finally obtainedthe main findings summarized as follows:1. PEF is found a highly efficient, non-thermal, continuous operationtechnology. It was found that the extraction rate of soybean oil increasedsignificantly with the increase of pulse by orthogonal test. The extraction rate wasincreased in the pulse at5. After that along with the increase in the pulse, soybean oil extraction rate increased and became more stable. Increased significance withthe increase in field reached the maximum in term of5kv/cm. Along with theincrease in field soybean oil extraction rate decreased slightly, and graduallybecame invariableness. It was found that the major factor affecting soybean oilextraction was pulse number by orthogonal test. It was the notable factor whoselevel of significance was0.05. Next one is field strength, and it was also thenotable factor whose level of significance was0.25and soybean: isopropanol wasalso the notable factor whose level of significance was0.25.2. The electric field intensity, pH, pulse number, stuff and liquid ratio andtemperature were the remarkable factors by PEF extraction pectin from pomace.And the electric field intensity was the most important factor. Then it was followedby pulse number; and pH was0.05, stuff and liquid ratio was0.05. The optimumparameter of electric field intensity, pH, pulse numbers, stuff and liquid ratio aredetermined by orthogonal test, i.e.3. When observing the erythroleukemia K562cells, which was induced by thehigh intensity pulsed electric fields detected with transmission electron microscope,we may find many vacuoles and crannies in cells, mitochondria swelling, vacant,shelvse of the inner membrane break, the hetero-chromatins are on the edge,nuclear pycnosis, nuclear fragmentation. The ultra-structure approves that the highintensity pulsed electric fields can make huge damage in K562cells and induceK562cells apoptosis. From the analysis of orthogonal array, we know when weinduce the K562cells apoptosis by the high intensity pulsed electric fields, the PEFstrength and pulse number are significant factors, therefore, the PEF strength isdominant and pulse extent is not significant. The best parameter combination isA1B3C3in the apoptosis of K562cells by PEF, which is the pulse extent, is1s,the PEF strength is25kV/cm, the pulse number is10and the PEF pulse is30Hz.The apoptosis rate is59.65%in the best condition. From the observation in FCM,we can find that the apoptosis rate of K562cells increases gradually along with thehoist of the PEF pulse number, when the PEF strength and pattern’s velocity offlow hold the line, and the biggest apoptosis rate of the K562cells is59.13%, P＜ 0.01, when the PEF pulse number is10. Meanwhile The apoptosis rate oflymphocyte cells achieve8.42%in10PEF pulse number from2.24%in4PEFpulse number, and when the pulse number is10, there is significant difference, P＜0.01. From the graphs of the K562cells and lymphocyte cells induced by the PEF,we can be conscious that the apoptosis rate of the K562cells and lymphocyte cellsis close in the change of the PEF pulse number, when the PEF pulse number is10,the difference in apoptosis rate of the K562cells and lymphocyte cells is thebiggest. When the PEF pulse number and pattern velocity of flow hold the line, theapoptosis rate of the K562cells increases along with the PEF strength, from the2.73%in0kV/cm PEF strength to86.81%in30kV/cm, and after20kV/cm PEFstrength, the apoptosis rate of the K562cells tends to immovability, which accountsfor the apoptosis action in the K562cells induced by the PEF is very notable.Besides in the same conditions, the apoptosis rate of lymphocyte cells alsogradually increases along with the PEF strength, when the PEF strength is20kV/cm or bigger, the apoptosis curve of lymphocyte cells tends to be smoothedline, and there is the biggest apoptosis rate47.08%in30kV/cm, P＜0.01.4. A theoretical analysis of PEF mechanism modeling was studied.Shrinking-core model for multi-passage was advanced and Dynamic models wereestablished and it was validated for the solid theoretical foundation for the future ofthe widely used of PEF. It is the least20kV/cm electric field intensity; more2pulsenumbers to damage cell membrane non-reversibly. Electric field intensity isdecisive factor to damage K562cell membrane, and the pulse numbers decides theexistent duration of cell membrane structural changes. But it is improper toincrease the electric field intensity and pulse numbers overly.In summary, PEF technology has the advantages of non-thermal, reactionspeed quick, efficient, easy to operate and low cost. It has significant social benefit and economic benefit.