Production of a fiber-enriched pasteurized and non-pasteurized fermented acidified drink using gellan

•A stable and fiber-enriched Doogh, an Iranian fermented drink, was produced using gellan.•Pasteurization effect on rheology, stability and sensory attributes of the Dooghs was analyzed.•Flow behavior of Dooghs with fiber and gellan changed from Newtonian to a shear-thinning liquid.•Enriched Dooghs were stable during storage but 55% phase separation occurred in control samples.•The samples overall acceptability with 0.4% fiber was high from taste panelist view.

Among dairy products, Doogh, a traditional fermented acidified drink, has special status in Iran due to its health properties. However, the main physical problem of the product is its phase separation. Therefore, the aim of this study was to produce a stable and fiber-enriched pasteurized and non-pasteurized Doogh using gellan. Pasteurized Dooghs containing fiber and gellan with constant shear rates had higher shear stresses and apparent viscosities than non-pasteurized samples. Moreover, pasteurization of the Dooghs led to an increase in the consistency coefficient and a decrease in the flow behavior index as well as an increase in the plastic viscosity and yield stress. The heat-treatment of the Dooghs resulted in a more pseudo-plastic behavior. The new products were stable during storage; however, about 55% phase separation occurred in control samples. Addition of 0.4% (w/w) fiber and gellan led to an acceptable appearance, odor, taste, off-flavor, consistency and overall acceptability.