Design, construction and performance evaluation of an Àmàlà making machine

Abstract

An àmàlà making machine was designed and constructed to make àmàlà preparation an easy one and remove the fatigue usually experienced during manual preparation. The machine frame was from galivanised and stainless steel materials and it is capable of preparing àmàlà of averagely 1.074–2.68kg by weight. It has two compartments, the heating and stirring compartments. The stirrer has six flat paddles arranged asymmetrically and powered by a 0.94HP electric motor. The performance evaluation of the machine revealed that the output by weight is significantly different (P<0.5) indicating that weight is not equal due to different input. There was reduction in weight with decrease in temperature of the paste from 90–66°C residence time 5–2.5min and quantity of heat stored by the paste from 210.16–8.64KJ as the input reduced. The density of the paste increases as the volume of water reduces (1223.83kg/m3 at 1.8 Litre of water to 2303.33kg/m3 at 0.6 Litre of water). Although, pastes produced at various ratio of yam flour and water are adjudged suitable by panellists in terms of colour, taste, aroma during sensory evaluation test, but 0.5kg of flour produced overall acceptable paste with 1.8 Litre (maximum pot capacity), while 0.35kg of flour produces overall acceptable paste with 0.6 Litre (minimum pot capacity)in term of modability, and texture.