The Studies Of Volatile Components And Unsaponifiable Matter Of Strong Fragrant Peanut Oil

The aim of this study was to separate and identify volatiles in expressed and solventextracted peanut oil using static headspace method combined with gas chromatography-massspectrometry (GC-MS).44kinds of volatile components were identified from5samples ofexpressed peanut oil and115volatiles were identified from5samples of solvent extractedpeanut oil by comparing their mass spectra with those contained in the N IST mass spectraldatabase and with some references.The main approaches of volatiles in peanut oilare:(1)Baked peanut kernels at temperature190℃, peanut protein and carbohydrate happenmaillard reaction, produce different alkyl substituents of pyrazine substance;5samples ofexpressed peanut oil [except HS005(A)] have different alkyl of pyrazine and pyrrolematerials,respectively2-methyl-pyrazine,2,6-two-methyl-pyrazine,2,5-two-methyl-pyrazine,2-ethyl-6-methyl-pyrazine,2-ethyl-5-methyl-pyrazine,2-butyl-3,5-two-methyl-pyrazine,N-methyl-pyrrole;but5samples of solvent extracted peanut oil weren’t identified pyrazine substances.(2)fatty acid esters were degraded by thermal and thermal degradation products causedsecondary reaction.Hydrocarbons and aldehyde compounds are the main volatile componentsin expressed and solvent extracted peanut oil, hydrocarbons is mainly pentane, n-heptane,butane, n-hexane,methyl cyclopentane and aldehydes compounds mainly includedhexanal,(E,E)-2,4-decadienal, nonanal.(3)volatile components of HS013(B) were identified asmall amount of thiophene, pyrimidine and pyrrole,because thermal degradation products andthe small amount of protein,the amino acid existed in peanut oil caused non-enzymaticbrowning reaction.It was analyzed the fluorescent substance of peanut oil, soybean oil, rapeseed oil withfluorescence spectra.. It showed fluorescence spectra of the kinds of vegetable oil and fat arethe same; but fluorescence spectra of the different kinds of vegetable oil and fat are not alike.It suggested that there are the same fluorescent substance in the kinds of vegetable oil and fat,different fluorescent substance in the different kinds of vegetable oil and fat. Fluorescentsubstance are mainly vitamin E (α, β, γ, δ-tocopherol), pigment, vitamin A and Aflatoxins invegetable oil and fat.84samples of peanut oils, soybean oils, rapeseed oils were identified bymathematic model SIMCA based on their emission spectra and synchronous fluorescencespectra. Samples type, sample structure, the principal component and spectral pretreatmentmethods influenced identification accuracy of SIMCA.The results show clustering accuracy and recognition accuracy of SIMCA analysis is100%. It is concluded that fluorescenceanalysis combined with mathematic model SIMCA recognition analysis are high sensitivity.Contour spectra of99samples of peanut oil, soybean oil, rapeseed oil, sesame oil, cornoil, sunflower oil, rice bran oil and cottonseed oil were characteristic information. Sampletypes and microcomponent’s structure is the main factors of contour map analysis. The resultsindicate that it is a feasible method to distinguish them based on the trend of contour spectraof vegetable oil.