Caffeine as a flavor additive in soft-drinks

Appetite. 2007 Jul;49(1):255-9. doi: 10.1016/j.appet.2006.11.003. Epub 2006 Dec 26.


Over 60% of soft-drinks sold in the United States contain caffeine, a mildly addictive psycho-active chemical, as a flavor additive. Using sweeteners as controls, we assessed whether caffeine has flavor activity in a cola soft-drink. A forced-choice triangle discrimination methodology was used to determine detection thresholds of caffeine in sweeteners and a cola beverage. The subjects (n=30, 28 female, 23+/-4 years old) were trained tasters and completed over 1600 discrimination tests during the study. The mean detection thresholds for caffeine in the sweet solutions were: 0.333+/-0.1mM sucrose; 0.467+/-0.29 mM aspartame; 0.462+/-0.3mM sucralose, well below the concentration in common cola beverages (0.55-0.67 mM). A fixed concentration of caffeine, corresponding to the concentration of caffeine in a common cola beverage (0.67 mM) was added to the sweeteners and a non-caffeinated cola beverage. Subjects could distinguish between caffeinated and non-caffeinated sweeteners (p<0.001), but all subjects failed to distinguish between caffeinated and non-caffeinated cola beverage (p=1.0). Caffeine has no flavor activity in soft-drinks yet will induce a physiologic and psychologic desire to consume the drink.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Appetite / drug effects*
  • Aspartame / administration & dosage
  • Caffeine / administration & dosage*
  • Carbonated Beverages / analysis*
  • Dietary Sucrose / administration & dosage
  • Female
  • Flavoring Agents / administration & dosage*
  • Humans
  • Male
  • Sucrose / administration & dosage
  • Sucrose / analogs & derivatives
  • Sweetening Agents / administration & dosage
  • Taste / physiology*


  • Dietary Sucrose
  • Flavoring Agents
  • Sweetening Agents
  • Caffeine
  • Sucrose
  • trichlorosucrose
  • Aspartame