Study On The Effect Of Different Sites And Extraction Methods On The Quality Of Camellia Oil

Camellia oil,also known as Camellia seed oil,is a high-grade healthy edible vegetable oil comparable to olive oil,with high nutritional value and health-care functions.With the improvement of living standard and the deepening understanding of camellia oil,the research on the quality and function of camellia oil has become a hot spot in recent years.However,there are few researches on the difference of camellia oil quality,the difference of extraction methods and the comprehensive evaluation of camellia oil quality.In this study,9 different locations of Camellia oleifera seeds were selected,and 3 methods were used to extract camellia oil.We analyzed the effects of site factors and extraction methods on oil yield and camellia oil quality,established a comprehensive evaluation model of camellia oil by principal component analysis,and evaluated the camellia plant oil quality based on principal component score and comprehensive quality score on different sites and different extraction methods.The aim of this paper is to establish a set of methods suitable for the evaluation of camellia oil quality and to provide a site basis for the realization of intensive and large-scale cultivation of Camellia oleifera and provide some reference for oil brand building.The main results are as follows:(1)The study on the extraction rate of camellia oil from 9 sites and 3 extraction methods showed that:the site had a significant effect on the oil extraction rate of camellia oil,while the aspect factor and slope factor had no significant effect on the extraction rate of camellia oil;extraction method has a significant impact on the oil yield of camellia oil,leaching method of the oil extraction rate(43.38%-50.81%)is higher than the pressing method(21.75%-28.54%).(2)The physical and chemical indexes of camellia oil in 9 sites and 3 extraction methods showed that the acid value(0.47mgKOH/g-0.54mgKOH/g)and peroxide value(0.72mmol/kg-1.56mmol/kg)of camellia oil at different sites and different extraction methods were lower than those of the first grade oil of the national standard.The site value has no significant effect on the acid value and refractive index of camellia oil,but has a significant effect on the peroxide value,iodine value and saponification value of camellia oil.The slope factor had no significant effect on the physical and chemical indexes of camellia oil,while the aspect factor had some influence on the peroxide value,iodine value and saponification value.The refractive index,the iodine value and the saponification value had no obvious effect on the camellia oil's extraction index,and had a significant effect on the acid value and peroxide value of the camellia oil.(3)The sensory quality and fatty acid composition of camellia oil in 9 sites and 3 extraction methods showed that:the site and extraction method had a significant effect on the sensory quality of camellia oil,but the aspect factor and slope factor had no significant effect on the sensory quality of camellia oil.There was no significant difference in the quality of the camellia oil among the five fatty acids,which were oleic acid,palmitic acid,linoleic acid,stearic acid and linolenic acid.The total unsaturated fatty acid content reaches 88.76%-91.14%.There were some differences in the fatty acid composition of camellia oil.However,there was no significant difference(P>0.05)between the fatty acid compositions of camellia oil and linolenic acid extracted by different extraction methods.The aspect factor and slope factor had no significant effect on the fatty acid composition of camellia oil.(4)The analysis of the functional components and the induction time of camellia oil in 9 sites and 3 extraction methods showed that the total phenol content of camellia oil in different sites was 6.85mg/kg-14.01mg/kg,vitamin E content was 122.90mg/kg-361.13mg/kg,and squalene content was 189.27mg/kg-419.08mg/kg.The total phenol content of camellia oil with different extraction methods was 3.91mg/kg-9.81mg/kg,vitamin E content was 81.91mg/kg-237.00mg/kg,and squalene content was 118.51mg/kg-261.37mg/kg.The site and extraction methods had significant effect on the content of total phenols,vitamin E and squalene in camellia oil.There was no significant difference in the content of total phenolics,vitamin E and squalene in the camellia oil from the aspect factor and slope factor.The oxidation induction time of camellia oil from different sites was 2.36h-3.67h,and the oxidation induction time of camellia oil from different extraction methods was 1.50h-2.94h.The site and extraction methods all had some effects on the oxidation stability of the camellia oil.The aspect factor and slope factor had no significant effect on the oxidation of camellia oil.(5)The principal components analysis was made on the comprehensive quality of camellia oil in 9 sites and 3 extraction methods.The mathematical model of camellia oil quality score in different sites was established as follows:f=(5.272*F1+ 2.877*F2+2.390*F3+1.371*F4)/11.910,the mathematical model of the camellia oil quality score with different extraction methods was f=(9.587*F1+3.413*F2)/13.000.According to the model,the scores of the comprehensive quality scores of camellia oil from the 9 sites were in the order of west slope>south downhill>west downhill>west uphill>south slope>east downhill>south uphill>east slope>east uphill,the 3 extraction methods from top to bottom of camellia oil quality scores in order of pressing method>aqueous method>leaching method.The comprehensive quality of camellia oil showed that the west slope is superior to the south slope and east slope in the aspect of slope direction,and the uphill is superior to the mid-slope and uphill in slope aspect.(6)The rankings of the main components of camellia oil quality in 9 sites and 3 extraction methods are not all the same as the ranking of comprehensive scores.The rank order of the main components of camellia oil quality in different sites showed that the camellia oil in the west slope and west downhill performed well in sensory quality,oxidation stability and fatty acid unsaturation.The oil yield and oxidation stability of the east downhill and the south downhill are better.The physical and chemical quality of the south downhill and south slope are better.The comprehensive quality score,sensory quality,oxidation stability and fatty acid unsaturation of west slope and downhill camellia oil are better.The rank order of the main components of camellia oil quality with different extraction methods shows that the sensory quality,physical and chemical indexes,oxidation stability,and fatty acid unsaturation of camellia oil obtained by squeezing method are better,and the functional ingredients of camellia oil by aqueous method is better.In summary,the site and extraction methods have significant influence on the oil extraction rate,physical and chemical indicators,sensory quality,fatty acid composition,functional component content and oxidation induction time of camellia oil.It indicating that the location and extraction method were two important factors that affected the quality of camellia oil.According to the comprehensive evaluation model,the rank order of the quality of camellia oil showed that best slopes of the comprehensive quality of camellia oil are the west slope and the south downhill,the worst on the east uphill and the east slope,and the other sites were on the center.The comprehensive quality of camellia oil on the west slope is better than the south slope and the east slope,the comprehensive quality of camellia oil on the downhill is better than the mid-solpe and uphill.The comprehensive quality of the pressing method camellia oil was higher than the aqueous method and leaching method oil.The rankings of the main components of camellia oil quality are not all the same as the ranking of comprehensive scores.