期刊名称：Western Australia. Fisheries Department. Fisheries Research Reports
印刷版ISSN：1035-4549
出版年度：2008
卷号：178
页码：435-435
出版社：Government of Western Australia / Department of Fisheries
摘要：This study examined the influence of different lupin varieties and their inclusion levels on the
physical features of an extruded fish diet. Lupin (Lupinus angustifolius and Lupinus luteus)
kernel meals of several different cultivars were included into mashes of a fish diet formulation
at 10%, 20% and 30% on a weight-for-weight basis. Soybean meal was also included in a series
of diets on similar basis as a reference. An unadulterated basal mash was also used as a 0%
inclusion reference. The diet mashes were extruded through a laboratory-scale APV 19:45 twinscrew
extruder. The operating parameters and screw-configuration were kept constant for each
diet treatment. The addition of water was also kept constant for each treatment. Each diet was
run through the extruder for 5 minutes before a sample of the pellets was collected for quality
analysis. Pellets were subjected to a range of quality analyses; including radial expansion, bulk
density, vacuum oil uptake, sink rate and shear strength. The inclusion of lupin kernel meal (either
L. angustifolius or L. luteus) was found to significantly increase bulk density, sink rate and shear
strength of the pellets. With this increase in lupin kernel meal inclusion level a concomitant
decline in vacuum oil uptake and radial expansion was also observed. Similar responses were
also observed with an increase in the inclusion of soybean meal. Most relationships were not
linear with inclusion level, but curvilinear, indicating that there were optimal inclusion levels
based on the other raw materials present in each formulation. Assessment of the diet mashes
using a Rapid Visco Analyser (RVA) showed that the inclusion of lupin kernel meals increased
the rate and degree of viscosity compared to a similar inclusion level of soybean meal. The
inclusion of lupin kernel meals in the diet mash was also observed to improve the water holding
capacity of the extrudate, which has important implications for the reduction in extruder wear.
Key features of the inclusion of lupin kernel meals on the pellet quality parameters were an
improved pellet hardness and moisture retention.
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