IDENTIFICATION OF POTENTIAL IMPACT ODORANTS IN FOUR TYPICAL MAPLE SYRUPS USING HEADSPACE SOLID-PHASE MICROEXTRACTION WITH GAS CHROMATOGRAPHY-MASS SPECTROMETRY

摘要

Maple syrup is the product resulting from the heating of maple sap tapped from sugar maple trees (Acer saccharum Marsh.). The commercial production of maple products occurs almost exclusively in North America. In 2007, Canada produced about 83% of the world's maple syrup with 5.1 million gallons of syrup valued at over $168 million. Maple syrup production is principally concentrated in the province of Quebec, which accounts for over 90% of Canadian production. The quality of maple syrup is currently evaluated using a grading system based essentially on colour and in which a better price is generally allowed for syrup with a lighter colour. However, consumer preference studies4"6 indicate that the commercial value currently assigned to maple syrup does not correspond to consumers' preferences for the various grades of maple syrup. While colour is known to be important for consumer acceptance of a product, sensory perceptions are requirements for the evaluation of food quality. The relationship between volatile compounds and the sensory quality of maple syrup has received limited attention, however. The highly complex composition of maple syrup has not yet been fully characterized. Over the years, scientists have succeeded in identifying some compounds in maple syrup that are suspected of being at the origin of its flavour. These include primarily phenolic compounds, carbonyl compounds, ' alcohols and acids, and pyrazines. However, the exact contributions of these compounds to the characteristic aroma and flavour of maple syrup are still uncertain. The objective of the present study was to identify volatile compounds in commercial maple syrups using HS-SPME-GC/MS, as well as to determine the possible contributions of those components to the typical flavour characteristics.