Study On The Synthesis And Application Of The Isothiocyanate Flavors

Isothiocyanate flavors are important food flavor compounds which contan sulfur and nitrogen atoms.Isothiocyanate compounds can be classified as alkyl isothiocyanate,alkenyl isothiocyanate,methylthio-containing isothiocyanate and aryl isothiocyanate compounds by the kinds of substituent groups.There are 19 isothiocyanate flavors in the list of “generally recognized as safe”(GRAS)setting by Flavor and Extract Manufacturers Association(FEMA).Among them,9 of them are alkyl isothiocyanate flavors,4 of them are alkenyl isothiocyanate flavors,4 of them are methylthio-containing isothiocyanate and 2 of them are aryl isothiocyanate flavors.In China,15 of the isothiocyanate flavors are allowed to use according to the standards for uses of food additives.The natural occurrence,odor characteristics,physical and chemical properties,formation mechanisms and synthesis methods of isothiocyanate were introduced in this thesis.First of all,3-methylthiopropylamine was synthesized from 3-methylthiopropanol by chlorination reaction,alkylation reaction and hydrazination reaction,and the synthetic condions were optimized.Second,butyl isothiocyanate was synthesized with the starting materials,including butylamine,triethylamine,carbon disulfide and p-tosyl chlorideand the synthetic conditions were optimized.By changing substrates,nine alkyl isothiocyanates,one methylthio-containing isothiocyanate and and one aryl isothiocyanate were synthesized.The general reaction rules were discussed.The target compounds was synthesized with the starting materials,including organic amine,triethylamine,carbon disulfide and acetyl chloride.By changing substrates,7 isothiocyanate were synthesized.The volatile components in 4 kinds mustard oil available and 7 mustard paste on the market were extracted by solid-phase microextraction and analyzed by GC-MS in order to identify those isothiocyanate.These compounds were determined by qualitative analysis methods of MS,RI and authentic samples.These compounds were quantified by internal standard method.The qualitative and quantitativedate of isothiocyanates provide the basis for the application later.The odor characteristics and retention indexs of 11 isothiocyanates were evaluated and determined,which will be beneficial to the determination of isothiocyanatein the research of flavor analysis.According to the above quantitative and qualitative date of isothiocyanates,the application of the synthesized isothiocyanates in mustard oil was studied,which provided reference for the application of isothiocyanate flavors.