Nutrient composition of different lupin species as ingredients for aquaculture feeds in comparison to soybean

ORELLANA, PAOLA; ADRIÁN HERNÁNDEZ; PATRICIO DANTAGNAN; RUIZ, JOCELINE; LORENZO MARQUEZ; MORALES, GABRIEL A.

San Antonio, Texas, USA

Congreso; Aquaculture AMERICA 2017; 2017

The interest of using lupins as an alternative to conventional plant protein sources in aquaculture diets has been increasing in recent decades, especially in Australia, Chile and some European countries. Lupin seed proteins stand out among other legumes because of their unique chemical composition, low levels of non-nutritional components and bioactivity potential. The aim of the present study was to analyze the nutritional composition of eight different varieties from four main lupin species, namely Lupinus albus (Rumbo, Ramses), L. luteus (AluPro-CGNA A, AluPro-CGNA B,), L. angustifolius (Lila, Granotrade) and L. mutabilis (Pinta, Baer) distributed and/or produced in the Araucania region of Chile, in order to compare them with soybean (Glycine max) and further explore their suitability for incorporation in fish diets. The highest protein content (60 %, dry basis) was found in seeds from lupins belonging to L. luteus, while L. mutabilis varieties contained 52 % protein and approximately 20 % as oil, an amount similar to that found in G. max (40 % protein and 20 % lipids). In this sense, L. mutabilis can be considered as the strongest potential competitor of soybean since it possess both the nutritional advantage of providing high proportions of protein as well as oil. The lowest contents of protein and lipids were found in all varieties of L. angustifolius (40 and 10 % respectively). In terms of phytic phosphorus, the higher concentrations were detected in all varieties of L. mutabilis, L. luteus, L. albus and G. max (0.24-0.38 %) and the lowest amounts were observed in all varieties of L. angustifolius (0.11-0.15 %).  Based on these results, the possibility of using different lupin varieties as a protein source in aquafeeds is discussed. Taking into consideration that nutritional evaluation of alternative ingredients for aquaculture should be based not only on the concentration of components further research is required to elucidate the relative bioaccessibility and bioavailability of nutrients from these lupins in carnivorous cultured fish species.