Effect of particle size on flow behaviour and physical properties of semi-ripe plantain (AAB Musa spp) powders

This work was conducted to study the influence of particle size and shape on the flow behaviour of semi-ripe plantain powders. An improved plantain variety (Big Ebanga), two hybrids (FHIA 21 and PITA 3), and a local variety (Corne 1, as reference material) were powdered by successive drying, milling, and sieving into three granulometric classes: unsieved (<500 µm), fine fraction (<180 µm; class 1), and coarse fraction (between 180 and 500 µm; class 2), thus differing in particle size distribution. Physical properties (water activity, particle size distribution, shape factors) were characterised and flow properties (basic flowability energy, compressibility, fluidisability, cohesion, etc.) were investigated using the FT4 powder rheometer. Convexity of unsieved and fine powders was slightly higher than for coarse powders. Fine powders of all plantain varieties were found to have the lowest water activity and the lowest flowability in unconfined conditions. Unsieved and fine powders presented a fluidised state at the end of the FT4 standard aeration test and their minimum fluidisation velocity was low, confirming the good fluidisability of these powders.