Mixing processes for agricultural and food materials: 1. Fundamentals of mixing

In agriculture and food processing, mixing operations are often used to blend ingredients. For food products to be acceptable, it is necessary that the mixing results in a uniform mixture. In addition to ingredient blending, mixing is used to cause changes in the properties of doughs. Additional knowledge is needed on mixing of doughs and reformed meats. Design of mixing systems is seen as an art without a general systematic procedure being available. Mixing operations may be classified based on the properties of the mixture. Broad classes are solids, Newtonian fluids, non-Newtonian fluids and viscoelastic fluids. Mixing is accomplished by imparting forces to the mixture which creates motion. The expected generalized flows can be described by mathematical models; however, these models do not give the rate or degree of actual mixing. Mixing rate and degree of mixing have been described using statistical indices resulting from analysis of samples. Better methods of predicting mixing performance are needed.