An investigative study on the effects of mechanical parameters of an automated grain drinks processing machine on drink consistency

Abstract

A response surface methodology (RSM) has been utilized for investigating the dynamics of mechanical parameters of a developed automated grain drinks processing machine. Also, the optimal values capable of yielding low and high drink consistency were established. The machine integrates the blending of soaked grains, mixing of the slurry, extraction of the aqueous liquid and discharging of paste out of the machine all together in a single unit. Its mechanical parameters, which include blade type, basket orientation, and speed, have been investigated while drink consistency was used as performance characteristics. The experiment was based on a central composite rotatable design (CCRD). The result of the experimental revealed that the highest consistency of 7.67 was obtained from an interaction between 3 blades assembly, basket with half angle of 30º and speed of 1400 rpm, while the least consistency of 1.96 was obtained from an interaction between 4 blades assembly, basket with half angle of 40º and speed of 864 rpm. Numerical optimization carried out with the goal of maximizing the consistency revealed optimum values of 3-blade assembly, basket orientation of 46.89º and speed of 1400 rpm for consistency of 7.68 with a desirability of 0.999. But when the goal was to minimize the consistency the optimum values of 5-blade assembly, basket orientation of 50º and speed of 1000 rpm were obtained, while the milk consistency and desirability were 2.57 and 0.894, respectively. The blade type and the speed of rotation were the most influential variables affecting the drink consistency. The result of this study provided standard input machine variables capable of yielding soya milk with various consistencies to meet the consumer's desire.