Lupin: A promising alternative protein source for aquaculture feeds?

The rapid growth of the aquaculture industry has resulted in a perpetually increasing demand for fish meal, the default protein source in most compound feeds. Therefore, alternatives are being sought and the greatest interest has thus far been placed on proteins of plant origin, mainly soybean. However, the utilization of soybean is troublesome, as the abundance of many antinutritional factors in soybean products may yield adverse effects when fed to aquatic organisms, while soybean production is generally unsustainable and environmentally unfriendly. Plants of the genus Lupinus seem to be an interesting alternative to soybean due to their relatively favorable composition and regional availability. The aim of this review was to evaluate the possibility of using lupin-derived protein in aquafeeds. Previous research has shown that this raw material proved to be highly beneficial, for several species. The major focus has been placed on the application of lupin in the diets of salmonids (rainbow trout, Atlantic salmon), cyprinids (common carp), perciform fish (sparids, barramundi, tilapia) and shrimps. Most studies have shown that lupin may replace fish meal even at 40–50%, what is a highly promising result. However, significant discrepancies occurred when comparing the effects of different lupin species (narrow-leaf lupin, white lupin, yellow lupin) and their cultivars. Furthermore, the technological processing of seeds also needs to be taken into account, as it may distinctly modify their initial nutritional properties. Upon summarizing, the gathered data indicates that lupin could be an efficient fish meal substitute for aquafeeds, but future studies need to take into consideration the seed type and applied processing.