The Application Of Instrument Analysis In The Aroma Study Of Synthetic Spices

According to the raw materials,spices consists of naturals and synthetics.The types,quantity and quality of naturals are affected by some factors such as natural conditions and the processing,but synthetics are not restricted by natural conditions,people can arrange the production according to their actual demands.The quality of synthetics is stable.Their price is much cheaper than naturals.The innovation and quality improvement in flavor and fragrance are becoming more and more depending on new types of synthetics.With the improvement of modern scientific research and analytical technology,it has been possible to isolate and analyze structures of the main aromatic components in natural spices,providing an important theoretical basis for increasing the variety of synthetic spices and improving the aroma quality.The process of synthetic spices involves many organic chemical reactions,such as reduction,esterification,condensation,isomerization,bonus,etc.Because the organic chemical reaction is a complex process,it must be accompanied by some other side reactions.Some of the side reactions are difficult to remove in the process of distillation and they will be likely to affect the final product.Some of the side reactions is contribute to the aroma quality instead.Analyzing the relation between the molecular structure of the synthetic spices contained in the component and sensory properties is the topic of this paper.Chapter one:The introduction,I introduce the background and practical significance of this paper by discussing the definition,production,application and classification of synthetic spices as well as the common knowledge of flavor and fragrance.Chapter two:Aroma molecular structure and Odor quality evaluation,discussing the mechanism of aroma generation,the connection between aroma molecular structure and odor characteristics,and the classification of aroma.I find out the requirements of sensory evaluation and analysis.Chapter three:Analysis system and instruments design idea,I get an idea under the guidance of teacher Bo Wu,my leader-manger Guichun Xiao,Swiss instrument analysis expert Dr Hans and our sensory evaluation expert Lily He as bellowing:Using Thermal Desorption to concentrate aroma molecules of MDJ,isolating them with GC,identifying their structure with MS,evaluating odor quality by GC-O and assessors.My aim is to analyze the key aroma molecules affecting odor quality and provide a new research idea and analysis method for odor analysis.Chapter four:Test method and test results,we design the system of Thermal Desorption-GC-MS and GC-O combined device and conduct the experiment.Chapter five;The conclusions,through the design and experiment of this paper,we analyze 79 components(except four isomers of MDJ)in NHU's sample and evaluate themselves'sensory characteristics.The conclusion of the paper proves that TD-GC-MS-O is logical,and this set of the instrument is the base of our further research.