Maple syrup is a natural product obtained from the xylem sap of the sugar maple (Acer saccharum). Tapped during the end of the winter season in Canada and many other parts of North America, this sap contains around 2% solids. It may be concentrated through evaporation of water, leaving behind a syrup rich in sugars. Although a wide variability can exist in the sap content of individual trees, around 35 l of sap is required to produce 1 l of pure syrup. The sugars, mostly sucrose, together with various trace elements and organic acids and various phenolics, furfurals, flavour components and chromophores, some of which are formed during the concentration process, constitute maple syrup.
Of the various constituents, sucrose is the most prevalent sugar, accounting for 98–99,9 % of the dry matter of the sap, while amino acids, organic acids, phenolic compounds, hormones, minerals, salts and other compounds constitute the remaining 2% or less. In maple syrup, sucrose constitutes 68 ±4 %, glucose 0,43 ± 1,11 % and fructose 0,30 ± 0,54 %, while organic acids such as malic and fumaric acids constitute 0,47 ± 0,11 % and 0,004 ± 0,002 % respectively. Sucrose, the major component of maple syrup, can also be obtained from other, much less expensive sources such as beet or cane. Hence maple syrup can be adulterated with comparatively cheaper cane and beet sugars/syrups for economic gain. Adulteration of maple sap and syrup with sugars from other plants violates state and federal laws and defrauds consumers. Detection of adulteration is possible even though maple syrup naturally varies in sugar concentration from batch to batch. Maple syrups adulterated with beet and cane invert syrups can be detected on the basis of altered reducing sugar content. However, it is difficult to detect the presence of pure beet and cane sugar (sucrose) contents in maple syrup, because sucrose is the only predominant sugar in maple syrup.