Powdered β-glucan extracted from brewer’s yeast (Yestimun®) was incorporated into skimmed-milk yogurt at varying concentrations (0.2-0.8% w/w) to investigate its potential application as thickener. The effect of β-glucan fortification on the nutritional profile, microstructure, physicochemical properties, and texture of freshly prepared yogurts was investigated. Sensory evaluation was also conducted and was correlated with instrumental analysis. The addition of Yestimun® significantly reduced the fermentation time of the yogurt mix from 4h to 3h. Scanning electron microscopy revealed that β-glucan particles form small spherical clusters within the yogurt matrix. The majority of the physicochemical properties (syneresis, viscosity, colour, titratable acidity) remained unaffected by the incorporation of Yestimun® in the recipe. Textural properties showed a gradual increment with increasing β-glucan concentration. Hardness, total work done, adhesive force and adhesiveness increased by 19.27%, 23.3%, 21.53% and 20.76% respectively, when using the highest amount of Yestimun® powder. Sensory analysis (n=40) indicated that fortifying yogurt with Yestimun® at 0.8% (w/w/) concentration may affect the overall acceptance ratings, which was attributed to adverse flavor and aftertaste effects. However, the overall liking score of the yogurt (5.0/9.0) shows potential for commercialization of the product.
- brewer's yeast