Design, fabrication and performance evaluation of a powered soy-gari mixer

Abstract

Aprototype mixer consisting of a trough, rotating shaft and blade mounted on a shaft and driven by a 2 horse power electric motor was designed, fabricated and its performance evaluated at 50% of its capacity by volume for mixing of different particle sizes of gari namely small (1.18 mm), medium (1.70mm)large (2.30mm)and locally sieved, mixed with soybean flour and paste respectively. Results show that power requirement for mixing of soy-gari increased with the particle size and was higher in the mixture of gari and soy-paste (SGP) than gari and soy-flour (SGF). Small
particle sizes were found to mix faster than large ones for both SGFandSGP. It was observed that low speeds of rotation and low power requirement of the machine increased the mixing efficiency and throughput capacity. Water absorption capacity and least gelation concentration of all the samples decreased slightly with increasing particle sizes. On the other hand, bulk density and swelling index of all the samples consistently increased as the particle sizes became smaller. The results of Sensory analysis indicated that mixture of medium particle size of gari (1.70mm) with soy flour was rated as having the best quality and was therefore, recommended.

Key words: Design, Fabrication, Performance, Soy-gari, Mixing