Relate physical properties to sensory attributes of carbonated beverages.

Bulk sweeteners generate a variety of functional properties in beverages including sweetness, palatability, flavor, bulking, bitterness, masking sour notes, structure and mouthfeel. Diet beverages can approach the taste of regular beverages by using a blend of high-intensity sweeteners. Some properties, including bulking, structure and mouthfeel, though, remain significantly different.

Relating the physical properties of these beverages to their sensory characteristics is an important step in being able to understand why mouthfeel is different for beverages sweetened with alternative sweeteners than for beverages sweetened with bulk sweeteners. With this in mind, scientists at the University of Illinois measured brix, viscosity, water activity, carbonation, titratable acidity and the pH of 14 commercial carbonated beverages. Then they correlated the physical measurements to a descriptive analysis results of each product.

Brix (measured using a handheld refractometer), water activity and carbonation were measured at 10 C on freshly opened cans of 14 carbonated beverages. Titratable acidity (measured using an automatic titrator) and viscosity were measured on decarbonated beverages at 22 C and 10 C, respectively. Investigators also determined the pH of carbonated and decarbonated beverages.

Researchers compared these physical measurements to sensory results generated by a descriptive analysis panel previously conducted on the same products. They applied correlation analysis, principal component analysis, partial least squares and cluster analysis to analyze the data. Brix, viscosity and sweet taste were highly correlated and negatively correlated to water activity. Carbonated and decarbonated pH were highly correlated and negatively correlated to mouth coating. Numbing, burn, bite and carbonation were highly correlated to total acidity, citric acid and ascorbic acid and were negatively correlated to phosphoric acid.

A number of factors contribute to the perceived mouthfeel differences between diet and regular carbonated beverages. Modifying the physical properties of diet beverages, by adding or substituting ingredients to match those of regular carbonated beverages, will decrease the differences in overall mouthfeel between the two types of products.

Further information. Shelly Schmidt, Department of Food Science and Human Nutrition, 367 Bevier Hall, 905 S. Goodwin Ave., University of Illinois at Urbana-Champaign, Urbana, IL 61801; phone: [phone]; fax: [phone]; email: [e-mail].