Isotope dilution assays , aroma

QUANTIFICATION OF AROMA COMPOUNDS BY ISOTOPE DILUTION ASSAY (IDA)... 

Quantification of aroma compounds by isotope dilution assays... 

Blank, I., Milo, C., Lin, J., and Fay, L.B. 1999. Quantification of aroma-impact components by isotope dilution assay Recent developments. In... 

Schieberle, P. and Grosch, W. 1987. Quantitative analysis of aroma compounds in wheat and rye bread crusts using stable isotope dilution assay. J. Agric. Food Chem. 35 252-257. 

The important odorant, 2-acetyltetrahydropyridine (ACTPY), has already been mentioned in the previous section. ACTPY and ACPY play key roles in the aroma of popcorn.227 Freeze-dried maize contains relatively high amounts of proline (155), whereas ornithine is not detectable (< 5 mg kg ) Schieberle treated a low-molecu-lar-mass fraction of an aqueous extract of maize in different ways and determined ACTPY and ACPY by isotope dilution assay (Table 5.2). Steam-distillation extraction gave 130 times as much ACTPY than ACPY however, in the presence of added 2-oxo-propanal, the amount of the former was multiplied by 4, but that of the latter by 29. Dry-heating, as in popping, increased the latter further, but the former became undetectable. 

Blank, 1., Milo, C., Lin, J., Fay, L.B. (1999) Quantification of aroma-impact components by isotope dilution assay - Recent developments. In Teranishi, R., Wick, E.L., Homstein, 1. (eds.) Flavor Chemistry. Thirty Years of Progress. Kluwer Academic/Plenum, New York, pp. 63-74... 

Quantification of aroma-impact components by isotope dilution assays (IDA) was introduced in food flavor research by Schieberle and Grosch (1987), when trying to take into account losses of analytes due to isolation procedures. The labeled compounds have to be synthesized, the suitable fragments have to be chosen, and calibration has to be effected. A quantitative determination of ppb levels of 3-damascenone (Section 5,D.38) in foods, particularly in roasted coffee (powder and brew), was developed by Sen et al. (1991a). Semmelroch et al. (1995) quantified the potent odorants in roasted coffee by IDA. Hawthorne et al. (1992) directly determined caffeine concentration in coffee beverages with reproducibility of about 5 % using solid-phase microextraction combined with IDA. Blank et al. (1999) applied this combined method to potent coffee odorants and found it to be a rapid and accurate quantification method. They also concluded that the efficiency of IDA could be improved by optimizing the MS conditions. 

Granvogl M., Christlbauer M., Schieberle P. Quantitation of the intense aroma compound 3-mercapto-2-methylpentan- 1-olin rawand processed onions (Allium cepa) of different origins and in other Allium varieties using a stable isotope dilution assay. Journal of Agricultural and Food Chemistry, 52 2797-2802 (2004). 

W Grosch, A Sen, H Guth, G Zeiler-Hilgart. Quantification of aroma compounds using a stable isotope dilution assay. In Y Bessiere, AF Thomas, eds. Flavour Science Technology, 6th ed. Weurman Symposium. Chichester, England John Wiley Sons, 1990, pp 191-194. 

Blank, Ch. Milo, J. Lin, and L. B. Fay, Quantification of aroma-impact components by isotope dilution assay—Recent developments, Havor Chemistry. Thirty Years of Progress (R. Teranishi, E. L. Wick, and I. Hornstein, eds.), Kluwer Academic/Plenum Publishers, New York, 1999, p. 63. 

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