Open AccessTwin Screw Extrusion of DDGS‐Based Aquaculture Feeds 1
Author(s) -
Kannadhason S.,
Rosentrater Kurt A.,
Muthukumarappan K.,
Brown Michael L.
Publication year - 2010
Publication title -
journal of the world aquaculture society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.655
H-Index - 60
eISSN - 1749-7345
pISSN - 0893-8849
DOI - 10.1111/j.1749-7345.2009.00328.x
Subject(s) - expansion ratio , extrusion , absorption of water , materials science , pellet , ingredient , soybean meal , plastics extrusion , bulk density , solubility , moisture , water content , food science , zoology , raw material , composite material , biology , chemistry , ecology , geotechnical engineering , organic chemistry , soil water , engineering
Six isocaloric (3.65 kcal/g), isonitrogenous (35% dry‐basis [db] protein), ingredient blends were prepared with 0, 17.5, 20, 22.5, 25, and 27.5% distiller's dried grains with solubles (DDGS) and other ingredients (soybean meal, corn, fish meal, whey, soybean oil, vitamin and mineral mix). The blends were moisture balanced to 15% db, then extruded in a twin screw extruder using a 2 mm die at 190 rpm, and a 3 mm die at 348 rpm. Analyses of the extrudates included moisture content, expansion ratio, unit density, bulk density, sinking velocity, color ( L * , a *, and b*), water absorption, water solubility, and pellet durability indices. Increasing the DDGS level from 0 to 17.5% db resulted in decreased expansion ratios by 14.8 and 23.5% for the products extruded using a 2 and 3 mm die, respectively. No significant difference in expansion ratio existed for DDGS levels between 17.5 and 27.5% db for either die. The water solubility index (WSI) of the extrudates increased (25.2 and 24.0%) as the DDGS increased from 0 to 27.5% db for each die. The 0% DDGS had the highest expansion ratio and the lowest unit density, bulk density, and sinking velocity. The extrudates that contained 20 and 27.5% DDGS had the highest durability and sinking velocity values.