Caffeine is included as a “flavoring” in over 60% of soft drinks consumed in the United States and its inclusion has come under scrutiny in recent years. Recent trends have seen an increase in products containing elevated caffeine levels, marketed as energy drinks, but few data are available regarding the impact of higher caffeine levels on sensory perception of beverages.
Method:
This study examined the ability of assessors to discriminate between caffeinated and noncaffeinated solutions of increasing complexity. Individual assessor's caffeine threshold levels were determined and a forced-choice triangle test methodology (BS ISO 4120:2004) was used to compare caffeinated (0.12 and 0.48 g/L; comparable to both standard and energy drink levels) and noncaffeinated model beverages. The model beverages increased in complexity from simple water solutions to glucose-sweetened solutions; citrus-flavored solutions; and flavored, sweetened, carbonated solutions.
Results
: Results indicated that caffeine discriminative ability was influenced primarily by complexity of the carrier beverage, although assessors with lower caffeine threshold levels were better discriminators in simpler beverages. In the more complex beverages (flavored, sweetened, carbonated), there was no evidence to suggest that caffeinated and noncaffeinated samples were perceivably different at the levels examined.
Conclusion:
This study raises questions regarding the inclusion of caffeine as a flavoring in standard soft drinks.
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