Establishment And Test Of Fingerprints Of Volatile Component In Hazelnut Oil

Hazelnut oil is an advanced edible oil.There is oleic acid,linoleic acid,linolenic acid,palmitic acid and many kind of unsaturated fatty acid in hazelnut oil,all of which can help regulate blood lipid,prevent cardiovascular diseases,and have antioxidant capacity.Although hazelnut oil is expensive,it is a kind of high-level edible oil welcomed worldwide especially in Europe,America,South Asian,etc.Because hazelnut oil is of high cost,some merchants add other oil to simulate it in order to get more profit.To avoid this phenomenon,it is necessary to establish fingerprint spectrum of hazelnut oil to identify if the oil is pure.The volatile component is an important index to estimate the hazelnut oil.Since the place of origin,variety,extraction and processing method are different,there are some differences in hazelnut oil.This paper establishes a standard fingerprint spectrum of volatile substances in hazelnut oil according to hazelnut oil produced by different varieties of hazelnut and different extract method to estimate the quality of hazelnut oil.First of all,this paper optimizes the extract condition of the volatile substances in hazelnut oil.The three factors,extract time,extract temperature,and parse time,which are the main factors influence extract effect,are determined by single factor experiment.Response surface model is used to establish a relative regression model to confirm the technique condition of extraction.Linear equation of fitted was Y=8.10+0.78X₁+0.017X₂+0.84X₃+0.28X₁X₂+0.19X₁ X₃+0.029X₂ X₃-1.05X₁²-0.43X₂²-0.75X₃² The optimum extraction process is extraction temperature of 54.51?,extraction time of 36.19 min,parse time of 4.19 min.Extraction time has the most important influence on the result while extraction temperature and parse time comes second and the third,respectively.Considering the feasibility and convenience,the ultimate extraction process is extraction temperature of 55?,parse time of4 min,and extraction time of 35 min.Secondly,hazelnut oil extracted by different materials and techniques will go through headspace solid microextraction to analyse the volatile substances by GC-MS method.The results showed that there are 17 kinds of esters,10 kinds of alcohols,10 kinds of alkanes,9kinds if olefine aldehydes,8 kinds of olefins,5 kinds of acids,5 kinds of aldehydes,3 kinds of amines,3 kinds of imidazoles,and a king of furanone.Choosing the common peak of volatile substances referring to the chromatogram to establish the stand fingerprint spectrum of hazelnut oil,7 kinds of acids,5 kinds of aldehydes,3 kinds of esters,2 kinds of olefins,2kinds of alkanes,a kind of siloxane and a kind of furanone are selected.Stand fingerprint spectrum of volatile substances in hazelnut oil was established,and peak overlap ratio and correlation coefficient method are used to evaluate the similarity of the stand fingerprint spectrum of the hazelnut oil extracted from different materials and by different techniques.The results showed that the correlation coefficient was between 0.9-1.0,which matched the requirements of the similarity evaluation of fingerprint spectrum.The fingerprint of the volatile matter of hazelnut oil was analyzed by cluster analysis,the results were consistent with the similarity results,which showed that the volatile substances of hazelnut oil obtained by different varieties combined with different processing methods were similar,but for the hazelnut varieties,different methods of preparing hazelnut oil had certain influence on the volatile matter of the hazelnut oil.Lastly,peanut oil was added to the hazelnut oil in different proportion to test the stand fingerprint spectrum.GC-MS analysis showed that some chromatographic peak such as octanol,aldehyde,and capraldehyde,will decrease with the increasing of the proportion of peanut oil.To prove the veracity of the conclusion,included angle cosine method was used to compare the volatile spectrum of the hazelnut oil adulterated with peanut oil with the stand fingerprint spectrum.Through calculating its similarity and linear fitting of similarity and real adulteration,the fitted curve of hazelnut oil-peanut oil adulteration model was obtained.Linear equation of fitted curve of hazelnut oil-peanut oil adulteration model was Y=12818X³-31286X²+23678X-5615.9.Y is represented for adulteration ratio and X is represented for cos?,the ngle cosine.Determination coefficient of linear equation of fitted curve of hazelnut oil-peanut oil adulteration model was 0.996,which illustrated that the model fit well in the test.