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Extruded aquafeeds containing distillers dried grains with solubles: effects on extrudate properties and processing behaviour
Author(s) -
Mjoun Kamal,
Rosentrater Kurt A
Publication year - 2011
Publication title -
journal of the science of food and agriculture
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.782
H-Index - 142
eISSN - 1097-0010
pISSN - 0022-5142
DOI - 10.1002/jsfa.4536
Subject(s) - die swell , expansion ratio , plastics extrusion , food science , water content , chemistry , distillers grains , shrinkage , extrusion , moisture , materials science , pulp and paper industry , composite material , geotechnical engineering , engineering
BACKGROUND: The tremendous supply and low cost of distillers dried grains with solubles (DDGS) make it an attractive feedstuff for aquaculture diets. Also, several studies have shown that DDGS can be successfully fed to various finfish. The objective of this study was to evaluate the effects of inclusion rate of DDGS (0, 250, 500 g kg −1 ), feed moisture content (350, 450 g kg −1 ) and die opening area (die A = 18.85 mm 2 , die B = 3988.45 mm 2 ) on the properties of the extrudates and on processing behaviour using a single‐screw extruder. RESULTS: Increasing the inclusion rate of DDGS resulted in extrudates with lower unit density, bulk density, expansion ratio, water solubility index and brightness (Hunter L ) but higher redness (Hunter a ) and yellowness (Hunter b ). The increase in moisture content affected the extrudate properties in different ways: it increased bulk density, Hunter L , Hunter b and mass flow rate, whereas specific mechanical energy decreased at high moisture content. Increasing the die opening area primarily decreased expansion ratio of extrudates, power consumption and barrel temperatures but increased mass flow rate. CONCLUSION: Extrudates from all treatments exhibited high durability and floatability, and less energy was required to produce extrudates when DDGS was used compared with soybean meal‐based diets. The aquaculture industry can use this information to develop high‐quality feeds at low cost. Copyright © 2011 Society of Chemical Industry