Influence of gelatin and starch on the instrumental and sensory texture of stirred yogurt

The effect of the addition of gelatin and starch on the rheological and sensory texture properties of sweetened plain stirred yogurt was studied. Six samples were prepared: two with gelatin ( 3 and 6 mg/ g), three with starch ( 1, 5 and 10 mg/ g) and a control sample without thickener. Rheological measurements were performed and flow curves were modelled according to the Herschel - Bulkley rheological model. Also, sensory evaluation was carried out using a trained panel. The addition of gelatin and starch significantly affected the instrumental texture parameters ( Herschel - Bulkley's model parameters and syneresis) and the perceived sensory texture of yogurts. All sensory descriptors were well predicted by the partial least squares regression of the instrumental parameters. The addition of thickeners significantly reduced syneresis. Samples produced with 6 mg/ g of gelatin did not show syneresis and showed the highest sensory viscosity, creaminess and mouth- feel. Therefore, the use of 6 mg/ g of gelatin could be a reasonable concentration to use in the production of low- fat yogurts. The effect of the addition of gelatin and starch on the rheological and sensory texture properties of sweetened plain stirred yogurt was studied. Six samples were prepared: two with gelatin (3 and 6 mg/g), three with starch (1, 5 and 10 mg/g) and a control sample without thickener. Rheological measurements were performed and flow curves were modelled according to the Herschel-Bulkley rheological model. Also, sensory evaluation was carried out using a trained panel. The addition of gelatin and starch significantly affected the instrumental texture parameters (Herschel-Bulkley's model parameters and syneresis) and the perceived sensory texture of yogurts. All sensory descriptors were well predicted by the partial least squares regression of the instrumental parameters. The addition of thickeners significantly reduced syneresis. Samples produced with 6 mg/g of gelatin did not show syneresis and showed the highest sensory viscosity, creaminess and mouth-feel. Therefore, the use of 6 mg/g of gelatin could be a reasonable concentration to use in the production of low-fat yogurts.