Functional Yogurt with Increased Fiber: Chemical and Textural Modifications Induced by Oat Powder Fortification

الملخص

This work investigates the chemical composition, texture properties, rheology, and morphology of stirred yogurt as influenced by oat powder fortification. The yogurt samples were supplemented with 1%, 2%, 3%, and 5% oat powder and then analyzed over time. The chemical composition revealed an increase in total solids, dietary fiber, ash values with oat powder addition, while the concentration of proteins decreased because of the dilution factor. The pH values remained unaffected by oat fortification; thus, oat powder supplementation did not affect the fermentation process and its rate. Textural analysis showed significant improvements in yogurt hardness and cohesiveness at high oat powder concentrations.   Water holding capacities showed significant dose-dependent increase, thus leading to moisture retention and syneresis inhibition. The results were supported by FT-IR spectroscopy and revealed polysaccharide embedding in yogurt matrices without affecting proteins. Viscosity showed non-linear behavior; thus, yogurt samples supplemented with high oat fiber concentration (5%) regained their flowability by virtue of polysaccharide networks. Consequently, oat powder fortification at 3-5% concentration could be an interesting approach in designing high fiber-added functional yogurt products having better composition and characteristics.