Development of a stable low-fat yogurt gel using functionality of psyllium (Plantago ovata Forsk) husk gum

Psyllium husk gum (PHG) as an ideal fat replacer was utilized to improve the production of an industrial low-fat yogurt gel. The combined effects of critical structural components (PHG concentration (0.072-0.128%) and fat content (0.29-1.71%)) on the textural (firmness and syneresis), rheological (viscosity), and chemical (pH and total titratable acidity (TTA)) attributes of developed set-yogurts were investigated using response surface methodology (RSM). The second-order polynomial equations with high R(2) demonstrated a good agreement between experimental and predicted data. The optimal formulation for achieving optimal pH (4.39) and TTA (81% lactic acid), maximizing firmness (0.172 N) and viscosity (6.40 Pa s) and minimizing whey separation (36.21 mL/100g) was 0.12% PHG and 0.63% fat. Sensory characterization also revealed that the yogurts manufactured at optimal point had more aroma, texture and overall acceptability than the control yogurts.