Project Number: 6645-41420-004-01
Project Type: Reimbursable

Start Date: Sep 15, 2003
End Date: Sep 14, 2005

Objective:
To test the hypothesis that sourness perception in acid or acidified foods is dependent upon the concentration of organic acids in a product with at least one protonated carboxyl group plus free hydrogen ions. The specific objectives in meeting the general objective will be: (1) to determine sourness intensity of individual acids as a function of pH to evaluate whether all acids have about equal sourness and if multi-protic acids reach maximum intensity with only one carboxyl group protonated; (2) in water solutions, to test the relationship between acid species with at least one proton and sourness intensity with random mixtures of acids; (3) to validate any relationships found in objective 2 by creating acid mixtures and testing if they have a previously predicted sourness intensity; (4) to test the relationship between protonated acid species in a group of acidified vegetables and the sourness intensity with random additions of acid mixtures; (5) to validate relationships found in objective 4 by creating acid mixtures in acidified vegetable products and testing to see if they have the predicted sourness.

Approach:
A panel will be trained to quantitatively rate the sourness of mixtures of organic acids in water solution and organic acids to acidified vegetables such as dill pickles. The panel ratings of the degree of sourness of solutions or foods will be correlated with the total concentration of the protonated forms of the acids and the hydrogen ion concentration to evaluate whether our hypothesis concerning the ability of humans to perceive the intensity of sourness.

Project Team

McFeeters, Roger

Related National Programs

Quality and Utilization of Agricultural Products (306)