Dry powder coating for food and feed applications.

摘要

A dry powder coating process was adapted so that starch could be used as the main coating material. Using a pan coater (horizontal cylindrical reactor equipped with baffles), a series of starches and 2 plasticizers (glycerol and triethylcitrate) were tested for dry powder coating using microcrystalline cellulose beads as core particles. Coating was realised in 15-30 minutes and carried out at room temp. with a general coating efficiency of >=80%. Quality of the coating improved as powder grain size was reduced to <=30 mum. Powders with a range of particle sizes and non-spherical grains allowed better packing, and a more stable and homogenous coating. EM did not reveal coalescence of the powder. Plasticizers acted as binders, and coating stability was insured by capillary forces, and less by fusion of the powder grains. Starch type did not affect the quality of the coating, but the size of the grains was important. It is suggested that the conditions and materials used in this study may be compatible with food and feed applications.