2012 ASABE Annual International Meeting
A pilot-plant twin screw extrusion study was performed in two twice-replicated trials with the goal of producing vegetable-based protein feeds for juvenile yellow perch. Two isocaloric (3.06 kcal/g) experimental diets were balanced to contain 20% and 40% DDGS, and a constant amount (20 %) of fermented high protein soybean meal (PepSoyGen, PSG), as the fishmeal protein replacers, in combination with appropriate amounts of other required ingredients; crude protein content was targeted at 40 %. A fishmeal-based diet was used as a control. To obtain cohesive extrudates, extrusion processing conditions were varied, including conditioner steam (0.11-0.16 kg/min), extruder water (0.11-0.19 kg/min), and screw speed (230-300 rpm). Increasing DDGS from 0 to 40% led to a considerable rise in bulk density, L*, b*, and unit density, but to a decrease in aw and expansion ratio by 12.6, 14.4, 23, 21, 31, and 13 %, respectively. Compared to the control diet, the lowest unit density and the highest bulk density of 791.6 kg/m3 and 654.5 kg/m3 were achieved with the diets containing 20 and 40% DDGS, respectively; changes in DDGS content did not affect the extrudate moisture content, absorption index, or thermal properties. Raising DDGS content from 0 to 40% resulted in a curvilinear increase in water solubility and a* of the extrudates by 13.4 and 35%, respectively. All extrudates had high durability of more than 98%, and low aw of less than 0.5. Overall, this initial study yielded physically viable feeds for yellow perch. Further extrusion studies are needed to determine optimal DDGS-based diet for yellow perch.
American Society of Agricultural and Biological Engineers
Fallahi, Parisa; Rosentrater, Kurt A.; and Muthukumarappan, Kasiviswanathan, "Twin-screw Extrusion Processing of Vegetable-Based Yellow Perch (Perca flavescens) Diets Containing Fermented High Protein Soybean Meal and Graded Levels of Distillers Dried Grains with Solubles" (2012). Agricultural and Biosystems Engineering Conference Proceedings and Presentations. 93.