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A Taste for Fat

Taste

There is evidence for a direct role of the taste system in the consumption and preference of high-fat foods. Image: iStockphoto

By Russell Keast

Desensitisation to the taste of fat may be an important factor in the obesity epidemic.

Russell Keast is Associate Professor in the Sensory Science Group at Deakin University.

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The sense of taste presumably evolved to inform us about the nutritious or toxic value of potential foods. The primary organ responsible for the sense of taste, the tongue, contains taste receptors that identify non-volatile chemicals in the foods and non-foods we place in our mouth.

When food chemicals activate taste receptors, signals are sent from the taste receptors to processing regions in the brain. The signals are decoded by the brain and we perceive the taste of the food as one of five distinct qualities: sweet, sour, salty, bitter and umami (a savoury-like flavour that is very similar to chicken stock).

Taste can be regarded as a nutrient detection system. For example:

• sweet tastes are elicited by sugars, reflecting the presence of carbohydrates;

• sour tastes are elicited by free hydrogen ions, reflecting excessive acidity;

• umami is elicited by glutamic and other amino acids, reflecting protein content;

• salt is elicited by sodium and other ions, reflecting mineral content; and

• bitter reflects potential toxins in foods.

Excessive bitterness or sourness is aversive to us, and informs us that the food in our mouth may cause harm so the best action is to spit it out rather than swallow it. In contrast the qualities sweet, umami and salty are all appetitive, and tell us that the food contains...

The full text of this article can be purchased from Informit.