Study Of Bake Process Optimization Of Tartary Buckwheat Tea Based On Aroma Components Analysis

As an important representative of tartary buckwheat products,buckwheat tea is favored by the market and consumers because of its good flavor and healthy function.However,that there is no standard of buckwheat tea roasting process has prevented the development of buckwheat tea industry from moving forward for a long time.The flavor is an important factor of evaluating the quality characteristics of buckwheat tea.Also," tea aroma" determines the overall quality of the buckwheat tea samples.Buckwheat tea aroma is mainly formed in the roasting process.the volatile substances can be enriched using a certain aroma extraction method.Then it can be analyzed by gas chromatography/mass spectrometry(GC-MS).This study has optimizated the buckwheat tea roasting process by principal component analysis(PCA)combined with sensory evaluation,basing on aroma components.The results are as follows:The experiment that extract buckwheat tea aroma with different methods showed that: three methods that steam distillation,solvent extraction and headspace solid phase micro extraction(HS-SPME)can extract 52 kinds of ingredients of buckwheat tea volatile components totally.And there are differences between aroma components extracted with three methods.Thereinto,the method of steam distillation extracted 11 kinds of volatile components,solvent extraction extracted 15 kinds of volatile components and HS-SPME extracted 34 kinds of volatile components.The method of steam distillation is poor at acids and phenolic extraction.Solvent extraction greatly affected by the polar extraction agent.And the volatile components extracted by HS-SPME were more abundant and balanced,all types were successfully extracted basically and extraction rate is higher.Also HS-SPME was easier to operate.Therefore,compared with the other two extraction methods,HS-SPME method had advantage.The aroma components analysis of buckwheat tea baked in different conditions showed that: extracting and detecting the aroma components by HS-SPME combined with GC-MS,and then using the method of principal component analysis.PCA results showed that the cumulative contribution rate of the first four principal components can reach 75%,whichcan represent the original data information basically.The first principal component mainly represented ketone,aldehyde and phenol compounds.The second principal component mainly represented esters,alcohols and hydrocarbons.The third principal component mainly represented methoxy phenyl oxime.And the fourth principal component mainly represented acids.By establishing buckwheat tea aroma quality assessment model,we have been evaluated buckwheat tea quality assessment total score expression: F=0.25685F1+0.21325F2+0.17582F3+0.1066F4.Compared the results of sample buckwheat tea sensory evaluation with the calculating scores using this model,the difference is slight between this two methods.So,it can prove that the buckwheat tea aroma quality evaluation model which was set up in the study has objective evaluation function.And it can offer a new approach for buckwheat tea flavor quality evaluation,also be used for a reference of buckwheat tea process optimization.In two kinds of evaluation methods,YP-10 is the highest scorer.So the buckwheat tea baking process parameters can be optimized for baking 15 min at 180?.