2015.08.25 Sweetness Lab

Today we did a lab tasting different kinds of sugars and rating them on a scale of 0 to 200. I thought that sucrose, glucose, fructose, and galactose were sweet; maltose was kind of sweet; lactose, starch, and cellulose had pretty much no taste at all. This suggests that the structure of the sugar affects the sweetness. For example, monosaccharides (which have 1 ring of carbons) like glucose and fructose were the sweetest. Disaccharides (2 rings) like sucrose and maltose were also sweet, but not as sweet. Polysaccharides (multiple rings) were not sweet at all. The only exception to this rule seems to be lactose, which is a disaccharide but did not taste sweet to me.

Fructose tasted the sweetest, which makes sense, since it is frequently found in the form of high fructose corn syrup in manufactured goods to make them taste sweet. Plants also use fructose in fruits to store more energy in less space and to entice animals to come eat the fruits and spread seeds. Glucose, which also tastes sweet, is what plants make during photosynthesis. Sucrose (more commonly known as table sugar) is most commonly used to sweeten foods during baking and cooking. Galactose seems to be the sugar which gives milk its sweetness.

Sugar tastes sweet because all sugars have hydroxyl (OH) groups that interact with taste buds on the tongue, which actually clusters of cells which are connected to the brain by nerve cells. The sweetness of a sugar is related to the ability of the sugar to hydrogen bond to a protein-based receptor on the taste buds.

All the different kinds of sugars we tasted

References:

Binns, Corey. "What Makes Food Taste Sweet?" LiveScience. TechMedia Network, 09 Jan. 2013.

Web. 27 Aug. 2015. <http://www.livescience.com/32408-what-makes-food-taste-sweet.html>.

Shapely, Patricia. Why Is Sugar Sweet? University of Illinois, 2002. Web. 27 Aug. 2015.

<http://butane.chem.uiuc.edu/pshapley/GenChem2/B4/index.html>.