Influence Of Steam Explosion Pretreatment On The Camellia Seed Oil And Protein

Camellia(Camellia oleifera Abel.)is one of the woody oil plant where is unique in China.The oil is mainly found in camellia seed,and the content is 40-50%,in addition,camellia oil contains many healthy and beneficial bioactive compounds such as oleic acid,Iinoleic acid,phenols,tocopherols and sterols.The camellia seed cake by-product produced after the extraction of oil,and the protein content is 14%-20%.But,the tea saponin contained in camellia seed limits the extraction and utilization of carnellia seed oil,moreover,most of camellia seed cakes are unutilized except for a small amount which is used as fertilizer,aninal feed or fuel and its added value is relatively low.It is of great significance to improve the yield of camellia seed oil and the utilization rate of camellia seed cake protein,thereby increasing the added value of camellia seed.Steal explosion can be used for Inaterial pretreatment to improve material extraction yield and improve material properties.Therefore,in this study,Camellia oleifera was used as the research,and using steam explosion pretreatment for camellia seed to extract of oil and protein.The main findings are as follows:1.Free oil content had gradually improved with the Increase of pressure from 0 MPzi to 1.6 MPa,however,after 1.6 MPa,the yield dropped slightly for higher steam pressure;the free oil yield peaks showed at 1.6 MPa 30.Thus,1.6 MPa 30 s was taken as the optimal steam explosion conditions of treating camellia seed.2.According to the 1H NMR and FTIR analyses,the functional groups of the oils were not significantly affected by the steam explosion pretreatment.Scanning electron microscopy showed that the surface of camellia seed was pretreated,which revealed that steam explosion pretreatment efficiently proloted the release of oil and bioactive substances by destroying the cell structure of-camellia seed.3.Steam explosion pretreatment increased the content of oleic acid and unsaturated fatty acid,reduced the acid and peroxide value of the camellia oil.The iodine value of the canellia seed oil,the content of polyphenols,squalene,vitamin E and aroma species were improved.Steam explosion pretreatment also promoted the intermediate production of Maillard reaction 5-hydroxymethylfurfural under certain conditions.4.Effect of steam explosion on the functional properties of proteins.The results indicated that steam explosion significantly improved the protein solubility,water holding capacity and oil absorption capacity,foaming properties and emulsion properties.The pH,protein concentration,NaCI and sucrose concentration have different effects on protein foaming and foaming stability,emulsifying property and emulsion stability.The sucrose content has obvious effect on protein foaming capacity and emulsion properties with protein,but has no significant effect on foaming stability.In addition,steam explosion reduces protein particle size and zeta potential,and improve the thermal property of protein.5.The mechanism of steam explosion on the function of camellia seed protein.After the steam explosion treatment,the content of simple sugars and free amino acids in the camellia seed cake decreased,and the lightness of the protein was reduced,the glycosylation fluorescence is enhanced,the results indicated that the Maillard reaction occurs during steam explosion.In addition,FTIR and differential calorimetry(DSC)showed that the secondary structure of the protein changed after steam explosion,the?-helix,random coil and ?-turn content decreased and the ?-sheet content increased.The near-UV CD analysis showed changes in the tertiary structure of the treated protein.The occurrence and change of the physical and chemical processes have a significant impact on the improvement of protein function.