Coffee and Sugar: How Molecules Do and Don't Get Along

Sugar is a heavy-weight in our hot drinks. That is, when we ask for coffee with milk and sugar, the sugar isn't just sweetening it. That particular sweetener changes the chemistry--rearranges molecules--within the drink.

That's according to researchers led by Seishi Shimizu at the University of York's York Structural Biology Laboratory, who recently published their findings on how caffeine, sugar and water interact at the molecular level in hot beverages, in the journal Food and Function.

Coffee and tea's bitter taste partly derives from caffeine. So, caffeine molecules stick together when in water, a tendency that is enhanced by the addition of sugar, a release noted.

This isn't caused by the strengthening of bonds between water molecules around the sugar, though, these scientists say. Their research suggest that an affinity between sugar molecules and water make the caffeine molecules adhere to one another (or aggregate) in order to separate themselves away from the sugar said the release.

Because of this clumping of the molecules, we experience less of the bitter taste.

The researchers used statistical thermodynamics--an area of theoretical physical chemistry that links the microscopic realm with the world that we can see--to look at molecular-level interactions behind what we eat daily, as the release noted.

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