SENSORY RATINGS OF COMMERCIAL PLAIN YOGURTS BY CONSUMER AND DESCRIPTIVE PANELS

Ten trained panelists rated the intensity of sensory descriptors from 17 commercial plain yogurts, and 153 consumer panelists who consumed plain yogurt at least once a month evaluated the same yogurts for acceptance. Consumer responses were correlated with attribute ratings, and consumer responses and trained panel ratings were correlated with analytical measurements. There was a wide range in consumer hedonic ratings for all sensory factors with significant differences found for appearance and sweetness liking. Consumers found the vast majority of samples too sour and not sweet enough. Hedonic ratings for sweetness, sourness, appearance, and texture liking were positively correlated with overall liking. Samples rated highest in overall liking had sourness ratings closest to just right on the "just right" scale. Consumers responses for hedonic and just right factors differed by sex of respondent. Ratings for all descriptors by the descriptive panel were significantly different. Sourness, with high intensity ratings, was most important in describing plain yogurt. Samples rated most favorably by consumers had lower intensity ratings for overall intensity, sourness, acetaldehyde, saltiness, and astringency and higher intensity ratings for sweetness, milkiness, and cooked milk. Titratable acidity and pH were correlated with many trained panel descriptors important to consumer acceptability. Better control of pH by yogurt processors would result in more favorable sourness levels, which should increase consumer acceptability.