Effect of the Yam Starch (Dioscórea spp.) and Pectin on the Rheological Properties of Stirred Yogurt

10.19026/ajfst.16.5956

Pérez Jorge A.；Andrade Ricardo D.；Arteaga Margarita R.

Consistency coefficient ； flow behavior index ； flow curves ； hydrocolloids ； rheological models

Advance Journal of Food Science and Technology

16卷S期（2018 / 11 / 10）

207 - 213

英文

The aim of study was to evaluate the effect of the temperature and concentration of yam starch and pectin on the rheological properties of yogurt. A stationary test was performed using an MCR 302 (Anton Paar) rheometer with concentric cylinder geometry, varying the strain gradient in an ascending (0-100/sec) and a descending (0- 100/sec), at different temperatures (10, 20 and 30°C, respectively). Yogurts were made using two varieties of yam starch (＂Espino＂ and ＂Criollo＂) and different concentrations of yam starches (0.1, 0.3 and 0.5% w/w, respectively) and pectin at 0.3% w/w was used as a commercial reference. The experimental data were fitted to the power law models, Herschel-Bulkley and Casson. The model that best represented the rheological data was the power law (R^2≥0.977, MSE≤0.674). Yogurts with an addition of yam starch presented thixotropy and pseudoplastic behavior (0＜n＜1); However, when pectin was used at 30°C the behavior was dilating (n = 1.23). Yogurts with ＂Criollo＂ yam starch have higher consistency, while yogurt with an addition of ＂Espino＂ yam starch are more pseudoplastic and have less thixotropy.