Fortified Blended Food Base: Effect of Co-Fermentation Time on Composition, Phytic Acid Content and Reconstitution Properties

Abstract

Dehydrated blends of dairy-cereal combine the functional and nutritional properties of two major food groups. Fortified blended food base (FBFB) was prepared by blending fermented milk with parboiled wheat, co-fermenting the blend at 35 °C, shelf-drying and milling. Increasing co-fermentation time from 0 to 72 h resulted in powder with lower lactose, phytic acid and pH, and higher contents of lactic acid and galactose. Simultaneously, the pasting viscosity of the reconstituted base (16.7%, w/w, total solids) and its yield stress (σ0), consistency index (K) and viscosity on shearing decreased significantly. The changes in some characteristics (pH, phytic acid, η120) were essentially complete after 24 h co-fermentation while others (lactose, galactose and lactic acid, pasting viscosities, flowability) proceeded more gradually over 72 h. The reduction in phytic acid varied from 40 to 58% depending on the pH of the fermented milk prior to blending with the parboiled cereal. The reduction in phytic acid content of milk (fermented milk)-cereal blends with co-fermentation time is nutritionally desirable as it is conducive to an enhanced bioavailability of elements, such as Ca, Mg, Fe and Zn in milk-cereal blends, and is especially important where such blends serve as a base for fortified-blended foods supplied to food-insecure regions.