A Preliminary Study On Fingerprint Of Camellia Oil And Almond Oil

In this experiment,the physical and chemical indicators of camellia oil and almond oil are measured,fatty acids are analysed,fingerprints of fatty acids and volatile components are established as well as the establishment of adulteration model.The experiment provides a certain standard for camellia oil and almond oil which are commercially available.The results are as followed:Acid value and peroxide value vary a lot in 20 camellia oil samples.Acid value ranges from 0.7977mg/g(Chunyuan S17)to 6.2453mg/g(Xinshi S8).Peroxide value ranges from 1.1276mmol/kg(Wangling S7)to 18.7475mmol/kg(Dexing Honghua S11).It is also verified by UV absorbance in 232nm and 268nm.Because of good storage,acid value of 17 almond oil samples ranges from 0.7356mg/g(Longwangmao S6)to 4.1238mg/g(Tianxinggan S15).Peroxide value of 17 almond oil ranges from 0.5647mmol/kg(Liguangxing S14)to 13.8284mmol/kg(Baomei S11).Inspite of 2 samples,acid value and peroxide value of the rest samples are of little difference.Most of them meet national standards and show-high quality.The fatty acid compositions of 20 camellia oil samples and 17 almond oil samples from different sources are analysed using the method of gas chromatography.Minimum(g/50g)--maximum(g/50g)of palmitic acid,stearic acid,oleic acid,linoleic acid,linolenic acid and total unsaturated fatty acid content of the camellia oil samples are 2.85-5.21,0.28-0.76,18.51-29.01,1.08-3.56,0.01-0.18,20.10-31.76.Minimum(g/50g)-maximum(g/50g)of palmitic acid,stearic acid,oleic acid,linoleic acid,linolenic acid and total unsaturated fatty acid content of the almond oil samples are:0.62-1.36,0.42-0.86,11.87-19.99,3.87-9.67,17.55-27.02.At the same time,the fatty acid fingerprints of camellia oil and almond oil are established.After the calculation of similarity,it is found that similarities among the samples are no less than 0.985 in spite of some individual samples.It is concluded that 20 camellia oil samples and 17 almond oil samples from different sources have extremely similar fatty acid fingerprint features.The volatile components of 20 camellia oil samples and 17 almond oil samples are analysed using the method of gas chromatography.The result shows that there is a big difference among the volatile components of 20 camellia oil samples because of different origin,processing methods,storage methods and storage time.Processing methods play a predominant role among the factors.While the volatile components of 17 almond oil samples show the similarity in spite of different origins,processing methods,storage methods and storage time.Differing only in a certain ratio and amount.The similarity of volatile components fingerprint of adulterated samples and pure samples are calculated using the method of vector cosine.The results show that with the increase of adulteration,the similarity of volatile components fingerprint decreases linearly.When camellia oil doping rapeseed oil,the calculation model of similarity and adulteration are y=-4572.5x3+5637.4x2-2206.3x+364.05(R2=0.9939),applying to more than 25%of the amount of mixing.When almond oil doping rapeseed oil,the calculation model of similarity and adulteration are y=-2947.0x3+1254.9x2+77.661x+46.693(R2=0.9965),applying to more than 15%of the amount of mixing.