Food Chemistry

5.2 Aroma Analysis 357 Fig. 5.14.Odorants labelled with deuterium () or carbon-13 () as internal standard substances for isoto ...

358 5 Aroma Compounds Fig. 5.15.Isotopic dilution analysis of 2-furfurylthiol (FFT), 2-methy1-3-furanthiol (MFT) and 3-mercapto- ...

5.3 Individual Aroma Compounds 359 Table 5.14.Volatile compounds with high aroma values in French friesa Compound Concentrationb ...

360 5 Aroma Compounds Table 5.16.SomeStreckerdegradation aldehydesa Amino acid Strecker-aldehyde Odor precursor threshold value ...

5.3 Individual Aroma Compounds 361 5.3.1.1 Carbonyl Compounds The most important reactions which provide volatile carbonyl compo ...

362 5 Aroma Compounds Table 5.18.Furanones in food Structure Substituent/trivial name or Aroma Occurrence trade name (odor thres ...

5.3 Individual Aroma Compounds 363 (5.6) Fig. 5.16.Formation of 5-ethyl-3-hydroxy-4-methyl- 2(5H)-furanone from threonine by hea ...

364 5 Aroma Compounds Table 5.21.Sensory properties of volatilesulfur compounds Compound Odor Quality Threshold (μg/l)a Hydrogen ...

5.3 Individual Aroma Compounds 365 Fig. 5.17.Cysteine decomposition by aStreckerdegra- dation mechanism: formation of H 2 S (I) ...

366 5 Aroma Compounds (5.12) Some reaction systems, which have been de- scribed in the patent literature for the production of m ...

5.3 Individual Aroma Compounds 367 5.3.1.5 Thiazoles Thiazole and its derivatives are detected in foods such as coffee, boiled m ...

368 5 Aroma Compounds Fig. 5.21.Formation of precursors of 2-acetyl-2-thiazoline (according toHofmannandSchieberle, 1995) Fig. 5 ...

5.3 Individual Aroma Compounds 369 Fig. 5.23.Dependence on time and tempera- ture of the formation of 2-acetyl-2-thiazoline from ...

370 5 Aroma Compounds (5.14) (5.15) (5.16) The reaction pathway shown in Fig. 5.25 can be based on the identification of HOP as ...

5.3 Individual Aroma Compounds 371 Fig. 5.24.Formation of 2-acetyl-1-pyrroline (according toHofmannandSchieberle, 1998) Fig. 5.2 ...

372 5 Aroma Compounds Table 5.24.Pyrazines in food Structure Substituent Aroma Odor threshold value quality (μg/l; water) Trimet ...

5.3 Individual Aroma Compounds 373 (5.19) Table 5.25.Formation of aroma active alkyl pyrazines on heating alanine and 2-oxopropa ...

374 5 Aroma Compounds Table 5.26.Precursors and sensory properties of amines Amine Amino Odor acid Quality Threshold (mg/l) prec ...

5.3 Individual Aroma Compounds 375 Table 5.27.Phenols in food Name Structure Aroma Odor threshold Occcurrence quality (μg/kg, wa ...

376 5 Aroma Compounds Table 5.28.Pyrolysis products of some phenolic acids (T: 200◦C; air) Phenolic acid Product Distribution (% ...