Journal of Emerging Trends in Engineering and Applied Sciences: Research Areas

Article Title: Mechanical Device for Starch Extraction during Rice Flour Fermentation: Cost Effective and Product Quality Consistent Approach
by Egwari, L O

Abstract:
A fork-like paddle stirrer device designed and fabricated served dual functions in the batch rice fermentation; starch extraction and for aeration. The yield and characteristics of the device-associated fermentation was contrast with features from fermentation simulating indigenous practices using a wooden spoon stirrer. Contrasting features include continuous aeration with the device-associated system that ensured frequent microbe-substrate contact, higher percentage yield of starch and a short time to result (7 days versus 15 days with the wooden spoon stirrer). The wooden spoon stirrer system only permitted occasional agitation, yielded less starch but produced more quantity of protein-rich fermented rice granules. Lactic acid bacteria and yeasts were dominant fermentative flora and flourished at pH 3.5 to 4.5. The mechanical device consists of a long beam which furcated into five prongs. The prongs are made of two arms which bifurcate and a third arm that runs vertically from the base. The paddles are spade-like in shape with circular blunt ends. The paddles contain circular perforations with area of ?r2. This perforation serves as a sieve for extrusion of starch. The upper arm of the beam is attached to a thick rectangular beam at a fulcrum which allows it to rotate 360o and two flexible spring cords that make the device to move both upward and downward. These mechanisms of operation ensure efficient agitation and facilitated the processes of extraction and aeration.

Keywords: rice starch, extraction device, fermentation, aeration, fermentative flora

Download full paper