Study On Stability Of Oil Body And Associated Proteins Extracted From Camellia Oleifera

Camellia oleifera is a traditional oil tree species in China,and China's Camellia oleifera seed oil production accounts for about 90% of the world's total production.Camellia oleifera industry is also one of the industries that help Dabie Mountain concentrate on contiguous areas of poverty.Promote new technologies,develop deep processing,extend the Camellia oleifera industry chain,and increase added value as the primary task at this stage.This project uses Camellia oleifera seeds as raw materials to study the effects of p H,organic solvent demulsification,and thermal processing on the oil body and oil body protein of Camellia oleifera seeds during extraction.The main research contents and results are as follows:1.Effects of extraction p H on oil body stability and oil body protein of Camellia oleifera SeedsThis chapter studied the extraction of oil bodies from different p H water systems,after centrifugation and multiple washings,the oil bodies of Camellia oleifera seeds was obtained.Laser confocal microscope,Turbiscan and other means were used to observe the stability of the oil body under different p H,Na Cl concentration and temperature conditions.The results showed that the oil body was more uniformly dispersed under alkaline conditions(such as p H11),and the particle size was about 8 ?m;while the high temperature(up to 80-90?)had no effect on the stability of the oil body,and the particle size was stable at 10 ?m.Then SDS-PAGE combined with qualitative proteomics was used to study the differences in the types of oil body proteins obtained at different p H extractions,and to explain the reasons for the stability of oil bodies from this perspective.The results showed that the oil body proteins extracted under alkaline conditions were two types of oleosins with molecular weights of 14 k Da and 27 k Da,and there were many types of proteins obtained at near neutral p H(p H 6.3),Including some globulins,enzymes and aquaporins that were tightly bound to the oil-water interface.2.Effect of organic solvent demulsification on oil body deoiling and oil body proteinDemulsified oil bodies were combined with different organic solvents,and the lipid parts were removed to obtain oil body proteins.Elemental analysis,XRD,DSC,FTIR and other methods were used to study the structural properties of oil body proteins,and quantitative proteomics was used to study the inherent factors affecting oil body protein properties.The results showed that the crude protein content of oil body protein precipitated by cold acetone and ether was 68.9%,and the crude protein content of oil body protein precipitated by chloroform and methanol was 57.7%.There were some differences in the macroscopic surface morphology and crude protein content of the oil body proteins obtained by the two methods.FTIR measurement results showed that there was no significant difference in the group composition of the two proteins,but there were differences in the secondary structure of the proteins: The secondary structure of the oil body protein obtained from chloroform-methanol was mainly ?-helix,followed by ?-sheet and random coil,and there was also a small amount of ?-turn.However,the secondary structure of the oil body protein obtained by cold acetone-ether was mainly ?-helix and random coil,and there was also a small amount of ?-sheet and ?-turn.The XRD diffraction pattern analysis results showed that the XRD of the oil body protein obtained by the two methods appeared a sharp diffraction peak at around 2? of 9.0°,and the relative intensity of the diffraction peak decreased significantly at the 9°-15° stage,the relative intensity of the diffraction peak increased significantly at the 15°-20° stage,a diffraction peak appeared again around 20°.This diffraction peak was gentler than the previous diffraction peak,and the relative intensity of the diffraction peak at the stage after 20° decreased significantly.DSC analysis results showed that oil body protein can remain stable at higher temperatures.The thermal stability of oil body protein obtained from cold acetone-ether was higher than that of chloroform-methanol.In the proteomics results,the total number of proteins identified by cold acetone-ether precipitation was 1952,and the total number of proteins identified by chloroform-methanol precipitation was 1927.There were 89 significantly different proteins in the oil body proteins obtained by the two extraction methods,30 up-regulated proteins and 59 down-regulated proteins.3.Effects of pre-processing methods on oil body and oil body protein of Camellia oleifera seedsThe boiling and roasting were selected to pretreat the camellia oleifera seed separately,and then the oil body and oil body protein were extracted,and the effects of different processing methods(boiling and roasting at different times)on the obtained oil bodies were investigated.The results showed that after boiling and roasting for different time,the seed of Camellia oleifera and its oil body changed.The particle size distribution of oil bodies obtained after roasting Camellia oleifera seeds at 130°C for 5 min,7.5 min and 10 min was concentrated at about 10 ?m,but the droplet size was reduced compared with the size of oil bodies obtained from crude Camellia oleifera seeds.After boiling at 100°C for 20 min,the particle size distribution of oil bodies obtained from Camellia oleifera seeds was concentrated at about 10 ?m after 40 min and 60 min,but the droplet size also decreased compared with the particle size of oil bodies obtained from crude Camellia oleifera seeds.