Abstract
Yogurt is a popular milk-based product known for its nutritional benefits and effects on the large intestine. However, yogurt production faces challenges like texture, consistency, and syneresis. Hydrocolloids, such as gums and polysaccharides, can enhance yogurt's consistency and rheological properties. This research evaluates rooster comb extract (RCE) as a natural additive to improve stirred yogurt's properties during 21 days of storage at 4°C. Two treatments with 0.8 and 0.9 g of RCE were added to stirred yogurt. Results showed a decrease in pH (from 3.89 to 4.38) and microbial counts (> 10(7) log CFU/g), along with an increase in titratable acidity (1.03%-1.48%) in RCE-enriched yogurt (p < 0.05). The 0.8 g RCE treatment showed reduced syneresis, lightness, and setting time compared to the control (p < 0.05). Rheological analysis indicated thixotropic shear-thinning behavior, accurately described by the Herschel-Bulkley model. All samples displayed solid viscoelastic properties, with the storage modulus exceeding the loss modulus in the linear viscoelastic region. While flavor and overall acceptability declined in enriched samples compared to controls (p < 0.05), no significant differences were found in other characteristics, including texture, color, and aroma (p > 0.05). In conclusion, RCE is a promising natural hydrocolloid for producing functional stirred yogurt, offering potential consumer benefits.