Study of the influence of soy lecithin addition on the wettability of buffalo milk powder obtained by spray drying

Abstract

In this study, buffalo milk powder was produced with and without added soy lecithin. The fresh buffalo milk was partially skimmed, pasteurized, concentrated to 40% (mass percentage) of total solids and dried by spray drying. For the samples prepared with lecithin, its addition was made prior to the drying process in concentrations of 0.3, 0.5 and 1.0g of lecithin/100g of total solids in the concentrated milk. The effect of lecithin concentration on the moisture content, morphology, color, surface area, particle size distribution and wettability of the powdered milk produced was evaluated. The wettability was assessed by the static wetting test and the Washburn technique, the latter giving the water contact angle (θ) of the powder material. The addition of lecithin decreased the wetting time (ranging from 5 min to 63.9s) and θ (ranging from 89° to 81°, approximately) of the buffalo milk powder, but it did not show much influence on the moisture, morphology, color, surface area and size distribution of the powder particles.