Grinding is an energy intensive process and therefore, there is a need to look for avenues to save energy. It is difficult to determine the minimum energy required for a given size reduction process but with the help of theories such as Kick’s (Henderson and Perry 1970), Rittinger’s
] (Henderson and Perry 1970) and Bond’s (Bond 1961) laws, it has become possible to understand the energy requirements for grinding. All three models proposed for dry grinding have given reasonably good results based on the type of grinding: the Kick model for coarse grinding; the Bond model for intermediate grinding and the Rittinger model for fine grinding (Fellows 2000). Many grinding methods followed to obtain coriander powder involved hammer mill (coarse grinding), plate mills (domestic use), and pin mills (fine grinding). But whenever comparing different methods of size reduction, certain general criteria must be considered:
a) required throughput, b) required finished particle size, c) size and uniformity of feed material, and d) method of feeding and collecting. Further, particle size is the most important
single physical characteristic of solids. Control of particle size is an important factor because it allows better use of the material and to select more efficient particle size
distribution of ground product according to their potential application. There are several research journals exclusively dealing with particle size and technology. Unfortunately,
most of the research reported pertains to mineral and inorganic materials. There are only few studies dealing with various aspects of grinding studies pertaining to food materials available in literature.