DETERMINATION OF PHENOLIC COMPOUND PROFILES IN MAPLE PRODUCTS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A high-performance liquid chromatography method, using ultraviolet and electrochemical detectors, was developed for the analyses of phenolic and furfural compounds in maple products. The concentrations of compounds were calculated using external standards that conformed to linear behavior. Most of compounds identified in saps, concentrates, and syrups were related to lignin derivatives. Statistical analyses of data showed that 5-(hydroxymethyl)-2-furaldehyde (HMF) concentrations and phenolic profiles were significantly different as related to harvest time and maple products. Although HMF concentrations were not significantly different as related to the producers, a highly significant difference was observed for phenolic profiles. An increase in the relative proportion of phenolic acids and a decrease in that of aldehydes and alcohols were observed during the reverse osmosis of maple sap. The thermal evaporation resulted in an increase in the amount of HMF, ferulic acid, vanillin, and syringyl aldehyde with a concomitant drastic decrease in sinapic acid.