The spray-drying process involves several steps (Kuriakoseand Anandharamakrishnan, 2010; Verdurmen et al., 2004)such as atomization of the liquid feed, contact between theatomized feed and hot air, drying of the atomized feed and collision of particles. Collision of particles during drying can be divided into particle–particle and particle-wall collision the stickiness conditions of food powders depending on the oper-ating conditions. For amorphous materials such as dairy powders, stickiness is usually related to the glass transition temperature of the product (Adhikari et al., 2001; Boonyai et al.,2004). Depending on the measurement method the sticky point is considered to be 20–40◦C above the glass transition temperature