Study On Extraction Of Volatile Oil From White Orchid And Its Aroma Components

The content of this research is mainly divided into three aspects,namely,the optimization of the extraction process of white orchid volatile oil by hydrodistillation(HD),solvent(petroleum ether)extraction(SE)and supercritical fluid(CO₂)extraction(SFE).Obtain HD-volatile oil,SE-volatile oil,and SFE-volatile oil respectively.Gas chromatography-mass spectrometry(GC-MS)and gas chromatography-electronic nose(GC-O)are used to analyze the components of these three white orchid volatile oils to determine the key aroma components in the white orchid volatile oil;research on the application of orchid volatile oil in tobacco flavoring.(1)The optimal process conditions for HD-volatile oil are:soaking time 1.5h, material-to-liquid ratio 1:15,distillation time 5h,Na Cl addition ratio 5%,HD-volatile oil yield 0.63%;SE-volatile oil optimal process:extraction Time 3h,extraction temperature 45?,material-to-liquid ratio 1:10(m/m),the extraction yield of SE-volatile oil is the highest at5.26%;the optimal process of SFE-volatile oil is:the amount of entrainer is 1.0m L/g,extraction pressure 25MPa,extraction temperature 40?,extraction time 1h,SFE-volatile oil yield is 1.68%.(2)The result of component analysis of HD-volatile oil shows that 48 compounds separated from HD-volatile oil are mainly composed of 49.02%alcohols,14.86%esters,11.92%olefins,10.16%acids,4.33%phenols,2.13%aldehydes and other components;The sum of their peak areas accounted for 92.42%of the total area of volatile oil components of white orchids.Among the 48 white orchid volatile oil components identified,linalool has the highest content,accounting for 38.72%,followed by linalyl formate 7.96%,elaidic acid 6.45%,phenethyl alcohol 6.09%,?-elemene 5.01%.The composition analysis of SE-volatile oil showed that 47 compounds were separated from SE-volatile oil,mainly consisting of 54.21%alcohols,24.25%esters,5.77%ketones,4.65%acids,2.91%phenols,alkenes 2.05%and other components;The sum of their peak areas accounted for 93.84%of the total area of volatile oil components of white orchid.in addition,among the identified components,linalool has the highest proportion,accounting for32.35%,followed by linalyl formate 22.87%,phenethyl alcohol 17.53%.The composition analysis of SFE-volatile oil showed that 63 compounds were separated from SFE-volatile oil,mainly consisting 74.52%alcohols,11.04%alkenes,5.65%phenols,2.87%esters,1.57%aldehydes,1.43%ketones,1.43%and 0.89%acids and other components.The sum of their peak areas accounts for 97.97%of the total area of volatile oil components.Among the identified components,linalool has the highest proportion,accounting for 49.66%,followed by(S)-oxylinalool 7.52%,trans-linalool oxide 7.11%,and?-elemene 6.26%.2,6-Dimethyl-3,7-octadiene-2,6-diol 2.85%etc.(3)SFE-volatile oil has a fresh and natural fragrance,with obvious white orchid characteristic aroma;the smelling scent is more sweet and more prominent than HD-volatile oil and SE-volatile oil.(4)The comparative analysis of the volatile oil components found that SFE-volatile oil contains more low-boiling,volatile components,which are more and relatively higher than HD-volatile oil and SE-volatile oil.SFE-volatile oil has five characteristic aroma substances,which are linalool,citral,phenethyl alcohol,geraniol and trans-nerolidol,which are the key aroma components of volatile oil.(5)When added to cigarettes,the white orchid volatile oil has the effects of improving the sweet and floral aroma of cigarettes,fine smoke,and increasing the richness of smoke.Among them,SFE-volatile oil has the highest score,which better enhances the natural freshness and sweetness of smoke.