Thursday, June 30, 2016

NMR and Food Chemistry - Maple Syrup

Maple syrup is arguably one of the tastiest traditional Canadian condiments.  In honor of Canada Day (July 1), it is appropriate to take a look at this delicious golden treat.  The bottom trace of the figure below shows the 600 MHz 1H NMR spectrum of pure Quebec maple syrup dissolved in D2O.
The spectrum is overwhelmingly dominated by sucrose.  Clearly, nature gives us the maple flavor with very low concentration components.  The top trace is a similar spectrum of "table" syrup which has a taste somewhat similar to maple syrup.  The spectrum is much more complicated than that of pure maple syrup.  In order to mimic the flavor of pure maple syrup, the food chemists resort to a complex mixture of sugars and artificial flavors.  Canada keeps it simple and of course better!  Happy Canada Day.

8 comments:

Anonymous said...

Is it true that someone who wants to get Canadian citizenship is obliged to eat 1 litre of maple syrup to prove that he likes it?

John Trant said...

Still looks like it might just be fructose and glucose as well as sucrose in the spectrum...happy Canada day Glen!

Glenn Facey said...

Anonymous,
Yes. Becoming a Canadian citizen is a very involved process. Aside from injesting a litre of maple syrup, one must kiss the cod, wear black and red plaid clothing, drink a two-four, eat a beaver tail, end sentences with "eh?" and of course apologize profusely for no apparent reason. It is all worth it though. It is great to be Canadian. Happy Canada Day!
Glenn

Txemi said...

Canadians are cheating in this comparison: their spectrum is taken at a much higher resolution so that all peaks will look much narrower. Just compare the width of the main peak at 4.7ppm!

Glenn Facey said...

Txemi,
Thank you for your comment, but with all due respect, I must disagree with you. The main peak at 4.7 ppm is due to water and the exchangeable -OH protons of the sugars. Its width is related to chemical exchange. I think if you take a close look at the spectra, you will see that the line widths of the sharper peaks are comparable between the spectra. In general, Canadians are very honest and polite people.
Glenn

Ieml said...

I prefer to freeze dry my maple syrup after a little journey in D2O ;-) - no cheating here but an even nicer spectrum.
Best wishes from North Wales (UK),
Martina

Anonymous said...

What pH was your maple syrup adjusted to achieve these peaks?

Glenn Facey said...

Anonymous,
I did not adjust the pH. I simply put maple syrup in D2O.
Glenn