Flavor Investigator: Maple

As a Canadian I am quite use to hearing people associate Canada with maple syrup. However, I don’t mind that association as Canada produces 80% of the world’s pure maple syrup and we do quite a good job at that! Maple syrup is a natural sugar product which is produced by evaporating water from the sap of the sugar maple, red maple or black maple. These trees are native to eastern regions of Canada and the northern parts of the Central and Eastern United States.  Overall, maple syrup is characteristically sweet, caramel-like, and brown with nutty and burnt notes.

Maple Syrup Grading

Although we associate maple syrup with a particular flavour profile there is range of flavours possible. In Canada all maple syrup sold must be graded and classified for colour. Therefore, we can associate different flavour profiles with the colour of the syrup. These grades are tested through the use of spectrophotometer and based on the percentage of light transmitted through the sample. The categories and their associated flavours/colours can be seen as followed:

Flavour Intensity

The group of compounds which dominate the flavour chemistry of maple syrup are pyrazines.  Pyrazines are aromatic organic compounds characterized as having a roasted or cooked flavour. That is why you are able to find them in other roasted products like peanuts, cooked meat and coffee.  Maple sap is boiled during processing which allows for the development of pyrazines. The creation of pyrazines are a result of the Mallard reaction, a non-enzymatic browning process responsible for darkening foods and is initiated by sugars and amino acids.  Some examples of the pyrazines found in maple syrup are methylpyrazine, 2,3- dimethylpyrazine and 6-methylpyrazine. The evolution and concentration of these pyrazines are dependent on temperature, heating time and the pH of the boiling of sap.

Maple syrup’s characteristic flavour profile is also a result of phenolic compounds. Similar to pyrazines, this class of compounds is associated with browning but in this case the browning of certain fruits like bananas or apples.  There are multiple phenols found in maple syrup including vanillic acid, vanillin, homovanillic acid and coniferyl alcohol. Research has shown that the later the sap is taken from the tree the higher the levels of phenolic compounds. Furthermore, conditions of the soil and climate also have a factor in this.

Finally, furfural compounds are also an important contributor to maple syrup flavour. Prior to the boiling process maple syrup furfural compounds will be found in low concentrations. However, this concentration will increase after the process and will help to develop a heavy, acrid caramel flavour.  Examples found in maple syrup are acetol, pineapple furanone, hydroxymethylefurfural (HMF). Furthermore, it has been found that the concentration of HMF increased as the season progressed suggesting an increase in caramel flavour in darker syrups.

Possible Unique Flavour Combinations For Maple Syrup

• Maple Syrup and Carrots- Carrots have flavour affinity for sugars as they are already sweet themselves. They have a woody and herbal notes which play off the “brown” notes associated with maple syrup.
• Maple Syrup and Brussel Sprouts- When cooked properly, brussel sprouts are nutty, bitter and cabbage like. This bitterness can be overwhelming but when the sugars of maple syrup are added this bitterness is lowered. As well, when they are cooked together in a browning preparation the “brown” compounds further develop in maple syrup-creating the perfect combination.
• Maple Syrup and Sour Cream- This combination is not to be eaten on it’s own but paired with another component. Sour cream is rich, creamy, tangy and has a subtle sweetness present from the cream. Maple syrup lightens the tanginess and creates a lavish flavour profile which pairs well with a sweet potato.