The effect of microbial transglutaminase and pumpkin peel on physicochemical, microstructural, and oxidative characteristics of camel milk yogurt during cold storage

The influence of MTGase treatment with and without pumpkin peel powder (PPP) on the physicochemical, oxidative, and other quality aspects of camel milk yogurt during refrigerated storage was studied. The MTGase-treated yogurt, with or without PPP, resulted in polymers with a smooth surface and high molecular weight. The total phenolic content (TPC) and antioxidant activity (DPPH) levels increased, while the thiobarbituric acid-reactive substances (TBARS) decreased in yogurt containing PPP during storage. The yogurt treated with MTGase and PPP exhibited significantly higher texture and rheological properties compared to yogurt made with MTGase alone. The yogurt pH decreased during storage, becoming more acidic. The addition of PPP enhanced the water-holding capacity (WHC), lowered syneresis, decreased the L* but increased b*, ΔE, and chroma (C*) values during cold storage<i>.</i> Bacterial counts in MTGase-treated yogurt decreased, but were not impacted by the inclusion of PPP during storage. In general, PPP and MTGase improved the overall qualities of yogurt during cold storage.