Influence of Pelletizing Conditions on Fabricated System Performance, Physical and Mechanical Properties of a Cassava Flour Based Fish Feed

Abstract

Conventional screw press fish pelleting machines are commonly used as a method of producing fish feed, but often affect the product properties. Manual pelletizers using hydraulic press instead of screw in a cassava flour-based diet can be easily processed, which can improve handling and storage. The influence of the pelletization parameters on some properties of cassava-based pellets was the focus of this study. The conditioning factors analyzed were: die size (4, 6 and 8mm), temperature (30, 60 and 90^oC), cassava inclusion (5, 10, 15 and 20%) and the influence of the mash moisture content (35, 40 and 45%) on the process and product responses. The quality of the pellets was evaluated in view of current standards. Second-order polynomials were applied to demonstrate the responses as a function of process factors. The studied factors had significant effects on the process response (throughput) and pellet properties (durability and bulk density). Majority of the values of throughput, bulk density and durability of the produced pellets attained the standard limits. Pelletizer operated optimally with processing parameter at 6.0 mm die size, 60°C temperature, 40% moisture content and 20% cassava inclusion rate resulted in pellet temperature (64.4°C), moisture content (34.21%), throughput (932.26 g h^-1), bulk density (0.36 g cm^-1), durability (99.1%) and hardness (0.30 kN). Pelleted feed using a manual press device under high cassava containment improves the properties of the product. Therefore, the applicability of the response surface method to optimize the process variables is sufficient.