Quantifying food quality: The case of alkyl-methoxypyrazines in wine Conference Paper uri icon

abstract

  • Wine is the oldest alcoholic beverage, and the most commonly consumed in many countries, including France, Sweden, Italy and Argentina. Its sensory quality is dependent on the relative prevalence of the 200+ odorants known to influence wine flavor. Many of these odor-active compounds exist at trace concentrations, yet still exhibit potent effects due to their low detection thresholds in humans. An important example is 3-alkyl-2-methoxypyrazines (MPs), which are capable of tainting both grape juice and wine, yet possess sensory thresholds well below the sensitivity of established analytical methods. Here we describe the development of a method based on multi dimensional gas chromatography coupled with mass spectrometry and headspace solid phase microextraction (SPME-MDGCMS) that allows for the measurement of MPs in wine down to the low ng/L range. We then apply this method to a range of commercial wines (n=187) from 14 countries to elucidate for the first time the relative concentrations of all four MPs implicated in wine quality - 2,5-dimethyl-3-methoxypyrazine (DMMP), isopropyl methoxypyrazine (IPMP), secbutyl methoxypyrazine (SBMP) and isobutyl methoxypyrazine (IBMP). IPMP and SBMP concentrations were consistently lower than IBMP. DMMP was detected in approximately half of the samples, and was above the limit of quantitation in 87% of those wines, suggesting it contributes to the aroma of many wines, especially reds. These results illustrate the capacity of modern chromatography techniques to determine the prevalence and importance of trace compounds in food contamination and quality.

published proceedings

  • 6th International Metrology Conference, CAFMET 2016

author list (cited authors)

  • Pickering, G. J., Botezatu, A., Kotseridis, Y., & Inglis, D.

complete list of authors

  • Pickering, GJ||Botezatu, A||Kotseridis, Y||Inglis, D

publication date

  • January 2016