July 25, 2013
Explaining Tolerance For Bitterness In Chocolate Ice Cream
April Flowers for redOrbit.com - Your Universe Online
Manufacturers of ice cream add high levels of fat and sugar to mitigate the inherent bitterness of cocoa in chocolate ice cream. A new study from a research team at Pennsylvania State University reports consumers who prefer dark chocolate in solid form tolerate twice the amount of bitter ingredients in chocolate ice cream than those who prefer milk chocolate. To some consumers, the elimination of some added sugar and fats in chocolate ice cream may be acceptable.
"Our primary goal was to determine whether rejection thresholds for added bitterness in chocolate ice cream could be predicted by individual preferences for solid milk or dark chocolate," says John E. Hayes, Assistant Professor of Food Science and Director of the Sensory Evaluation Center, College of Agricultural Sciences, Pennsylvania State University. "Estimating rejection thresholds could be an effective, rapid tool to determine acceptable formulations or quality limits when considering attributes that become objectionable at high intensities."
Hayes and his team produced a control sample of plain chocolate ice cream. They also produced samples with varying levels of sucrose octaacetate, a food-safe bitter ingredient used to alter the chocolate ice cream's bitterness without disturbing other the sensory qualities of the samples, like texture. The findings of the study were published in a recent issue of the Journal of Dairy Science.
The research team offered samples in pairs to 96 members of the Penn State community. All the participants were non-smokers between the ages of 18 and 45. Each participant tasted one spoonful of ten different samples, rinsing their mouths with water between each pair. The researchers asked the participants to indicate which of the two blind samples they preferred after each pair. Forty-six people reported they preferred milk chocolate.
The group of participants that preferred solid dark chocolate showed a significantly higher rejection threshold, as expected. Their rejection threshold was approximately twice as high for sucrose octaacetate in the chocolate ice cream than the group that preferred milk chocolate.
"These results suggest that this approach could be used to make chocolate ice cream with less added sugar to be marketed for dark chocolate lovers, though this needs to be formally tested," says Dr. Hayes. "Rejection thresholds can also be applied to other dairy foods in quality control or product optimization applications as a means to determine specific concentration limits associated with preferences."
The team has also demonstrated the use of the rejection threshold methodology is effective with solid foods, not just liquids as previously thought.