Flow Behavioural Studies on Food Powders

This study focuses on characterizing the bulk powder flow properties of four food powders, namely, tomato, onion, mango, and raw banana. The characterization includes particle size and its distribution, shape, moisture content, loose bulk density, tapped bulk density, and porosity. The flowability of these food powders was determined using Hausner Ratio, Carr’s Index, and flow function. The flow function and wall friction tests were conducted using an annular shear tester based on Jenike’s shear cell technology. The instantaneous flow function results showed that the powder flow behaviour of mango was free-flowing, while onion and tomato powders were easy-flowing, and banana was difficult-flowing. After 12 hours of consolidation time, mango powder’s flow behaviour changed from free-flowing to easy-flowing, and the other three powders (banana, onion, tomato) moved towards cohesive difficult-flowing behaviour. The particle density of mango powder was the lowest (1389 kg m^-3) and onion was the highest (1536 kg m^-3). The particle size (d₅₀) of easy-flowing mango powder and difficult-flowing banana powder was 165 μm and 50 μm, respectively. The determined flow properties of the food powders can be used to enhance its handling during commercial operations.