Effect of Concentration of Fenugreek (Trigonella Foenum-Graecum L.) on the Physicochemical, Microbial Stability and Sensory Quality of Stirred Yogurt

Abstract

This study analyzed proximate composition, physicochemical properties, microbial stability, and sensory characteristics of stirred yogurt formulated with fenugreek (Trigonella foenum-graecum L.) extract and stored for four weeks. Yogurt was produced using standard methods by incorporating graded levels of fenugreek extract at 0.0, 0.1, 0.3, and 0.5% respectively. Weekly analyses were conducted using established standard procedures. Data were analyzed using mean, standard deviation and ANOVA at 0.05 level of significance. Results shows that moisture (83.74–84.85%), protein (11.61–12.06%), fat (0.31–1.79%), and carbohydrate (2.66–3.55%) contents increased as the concentration of fenugreek extract increased. No fiber was detected, while ash content ranged between 0.01–0.02%. The pH decreased steadily from 4.10 in week one to 3.85 in week four, with a corresponding rise in titratable acidity from 0.23 to 0.295% respectively. Lactic acid bacteria count ranged from 2.8–3.6 × 10⁵ cfu/g at day zero to 2.1–3.9 × 104 cfu/g at week four, showing no significant difference (p > 0.05) initially. Total viable counts followed a similar pattern. Sensory evaluation indicated that fenugreek extract up to 0.5% produced acceptable yogurt in terms of flavor, texture, and overall quality, enhancing nutritional, microbial, and sensory attributes while maintaining good storage stability for four weeks at room temperature.