FLOW CHARACTERIZATION OF AMBIENTLY AND CRYOGENICALLY GROUND BLACK PEPPER (PIPER NIGRUM) POWDER AS A FUNCTION OF VARYING MOISTURE CONTENT

The knowledge about flow properties of powders is important in case of developing powder processes and handling procedures, packaging practices and transporting the processed powders. Major flow-characterizing parameters such as angle of slide, apparent and tapped volume, poured and compacted densities, Hausner ratio, Carr index, compressibility index, different angle of repose and particle size distribution for black pepper powder (BPP) under ambient and cryogenic grinding conditions for different moisture contents (MC) were studied. Angle of slide was found to increase from 39 degrees to 51 degrees with increasing MC. Bulk density of porous and compacted BPP was found to decrease with increasing MC. The powder porosity was found to increase with increasing MC (25.9-27.4% for ambient grinding and 23.2-25.8% for cryogenic grinding). Hausner ratio and Carr index were higher in case of ambiently ground BPP as compared with cryogenically ground BPP. Static angle of repose was found to be higher for ambiently ground powder than for cryogenically ground powder, and showed an increasing trend in both the cases of ambient (65.85-70.25 degrees) and cryogenic grinding (62.7869.34 degrees) with increasing MC. The flow characteristics of BPP as a function of MC may aid in better selection/design of appropriate handling, transportation, packaging and processing practices for BPP.