Effect of incorporation of iron–whey protein concentrate (Fe–WPC) conjugate on physicochemical characteristics of dahi (curd)

Dahi samples were prepared from milk incorporated with spray-dried iron–whey protein concentrate (Fe–WPC) conjugate and ferrous sulfate (FeSO4) with three different concentrations of iron i.e. 15, 20 and 25 mg/L and their quality characteristics were determined. Fe–WPC conjugate incorporated dahi showed better sensory, textural and physical attributes as compared with those of FeSO4 fortified and control dahi. Non-significant (p > 0.05) changes were observed in attributes like acidity and flavor, color and appearance, body and texture scores of dahi fortified with Fe–WPC conjugate with upto 20 mg/L iron as compared to those of control. In contrast, definite metallic flavor was perceptible in case of FeSO4 incorporated dahi even at 15 mg/L level. Water holding capacity, viscosity and firmness were significantly (p < 0.05) higher in 20 mg/L Fe–WPC conjugate incorporated dahi samples as compared with those of 20 mg/L FeSO4 incorporated dahi samples. In vitro bio accessibility of iron from Fe–WPC conjugate incorporated dahi was found to be significantly (p < 0.05) higher than that from FeSO4 incorporated dahi. Therefore, the results indicated that Fe–WPC conjugate can be fortified in dahi with upto 20 mg/L without significantly altering its physicochemical properties and with a higher bioaccessibillity of iron.