Biochemical composition of maple sap and relationships among constituents

• Samples of maple sap were collected at different periods of the 2007 and 2008 seasons.
• Compound concentrations for sap collected using modern technologies are reported.
• Changes were observed in sap composition according to flow periods.
• Multivariate analysis illustrated the relationships that exist between compounds.
• We report a solid base of maple sap composition for its future use as raw material.

Maple sap is a product of great economic value with a variable composition. Samples of maple sap were collected at different periods of the 2007 and 2008 seasons in various locations in Quebec (Canada). The aim of the study was to establish a typical chemical composition of maple sap by analyzing a large number of maple sap samples. Multiple factor analysis was also performed to help establish relationships among compounds. Results confirm that total soluble solids and sucrose concentration were higher near mid-season. The concentration of specific organic acids in sap could depend on the sugarbush (malic acid) or could be influenced by microbial activity (acetic and lactic acid). Phenolic compounds of interest were present mainly at the beginning of the season and decreased as the season progressed. The concentrations of the main minerals (K, Ca and Mg) increased over the sap flow season and the presence of calcium and magnesium seemed highly correlated. These results will help in establishing an update of mean values and ranges for many components of maple sap.