Influence of Coriander Seed Powder on Texture, Rheological Properties, and Sensory Quality of Spoonable Yoghurt

This study investigated the effects of various concentrations of coriander seed powder (CSP) (0.1%, 0.3%, and 0.5%) on the fermentation performance, whey precipitation rate, texture, rheological properties, microstructure, and sensory characteristics of spoonable yoghurt stored at 4 °C for 21 days. The aim was to evaluate the impact of CSP on spoonable yoghurt quality and its health-promoting properties. The results revealed that the addition of CSP led to a significant decrease in pH and an increase in titratable acidity. Furthermore, the whey precipitation rate in the CSP-enriched yogurt sample was clearly lower than that of the control group (p < 0.05). The syneresis of the yogurt sample with 0.3% CSP decreased by 21.14 on the 21st day, compared to the control group (49.64%) (p < 0.05). This was accompanied by a reduction in apparent viscosity and an increase in the viscoelastic modulus. Meanwhile, the texture of the yogurt sample remains more stable, with the best sensory acceptance in the yogurt sample containing 0.3% CSP. As the concentration of coriander seed powder level increased, antioxidant activity, digestibility, and small molecule phenolic level of the yogurt samples obviously improved (p < 0.05). Yogurt with 0.3% CSP still showed significantly enhanced antioxidant capacity during the 21-day storage period. The DPPH-radical scavenging rate increased by 5.22% compared to the control group (p < 0.05). Similarly, the ABTS+ clearance activity increased by 12.52% (47.06% compared to 34.54% in the control group, p < 0.05). In the 0.3% CSP yogurt group, the total phenolic content reached 5.33 mg GAE/100 g, an increase of 1.85 compared to the control sample (3.48 mg GAE/100 g) (p < 0.05). The in vitro protein digestibility of the yogurt samples containing 0.3% CSP clearly increased by 12.65% (p < 0.05). In summary, the yogurt sample supplemented with 0.3% CSP demonstrated optimal sensory quality characteristics. Coriander seed powder may be used as a beneficial ingredient containing rich active substances to enhance the quality of spoonable yoghurt products.