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ARS Home » Plains Area » Brookings, South Dakota » Integrated Cropping Systems Research » Research » Publications at this Location » Publication #239645
Title: Extrusion of Aquafeeds Containing DDGS with Navy and Pinto Bean Flours

Author
item Rosentrater, Kurt
item TULBEK, MEHMET - Northern Crops Institute

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/2/2009
Publication Date: 9/13/2009
Citation: Rosentrater, K.A., Tulbek, M. 2009. Extrusion of Aquafeeds Containing DDGS with Navy and Pinto Bean Flours. AACC International Annual Meeting, Baltimore MD, September 13-16, 2009.

Interpretive Summary:

Technical Abstract: As the global population continues to grow, there is an increasing need to produce food. Aquaculture is a rapidly growing segment of agriculture, and is helping to meet some of this growing demand. The majority of protein for aquafeeds is fish meal. But due to growing costs and potential scarcity of fish meal supplies in coming years, there is an impending need to find alternative protein sources. DDGS, a coproduct of the fuel ethanol industry, may be suitable for this purpose. The objective of this study was to examine the effect of extrusion processing conditions on feed blends containing DDGS and other ingredients. Two aquafeeds were formulated using 20% DDGS, 14.75% soybean meal, 14.0% corn flour, 0.75% vitamin and mineral mix, and either 50% navy bean or 50% pinto bean flour. The blends were processed in a pilot-scale twin-screw extruder at speeds between 357 and 477 rpm, using a 3-mm circular die. The resulting extrudates were subjected to extensive physical property analysis, which included moisture content, unit density, bulk density, expansion ratio, sinking velocity, color (Hunter L, a, and b) and pellet durability index (PDI). Extruder parameters, including moisture content after the conditioner and at the die, as well as mass flow rate, were measured to quantify the extruder behavior during processing. All process settings produced viable extrudates which floated for more than 24 h. Extrudate bulk density ranged from 0.25 to 0.33 g/cm3; compressive strength ranged from 0.22 to 1.56 MPa, and PDI ranged from 85.8 to 92.6%. This study highlights the importance of experimentally quantifying the effects of feed ingredients and process variables when developing aquafeeds with novel materials.