Page 13 - Aquauclature Research and Studies (01)

AQUAUCLATURE
Research and Studies 1 (1): 15-01, 2026 page of 193
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1. Introduction
Aquaculture is the global fastest growing agri-food industry with an
annual growth of almost 9% (Toufique and Belton, 2014). The success of the
aquaculture industry is highly dependent on the prices of aquafeeds. Thus,
there is a need to identify new, high quality and more cost-effective ingredi-
ents that will enable the efficient growth of fish at a cheaper cost (Couto et
al., 2016). Soybean meal (SBM) is considered to be an alternative to fishmeal
(FM) in reducing feed cost (Storebakken et al., 2000) because it contains a
comparatively well-balanced amino acid profile and high protein (Chou et al.,
2004). On the other hand, the demand for FM and plant-based sources of pro-
teins including SBM, maize and wheat has risen among aquaculture and
farmed animals in recent years with a concomitant increase in the prices of
these legumes and grains. In most tropical countries, SBM and oils used in
the feed milling are imported and thereby increase feed costs (Azaza et al.,
2009).
SBM and carob seed germ meal (CSGM) have about same protein
content (>50%) and share a balanced amino acid profile except for the sulphur
amino acids (Dakia et al., 2007; Maza et al., 1989). CSGM may offer flexi-
bility as an aquafeed ingredient if it can fully or partially replace SBM. How-
ever, the presence of ANFs may limit the use of CSGM (Alexis, 1990). Gilt-
head sea bream shows a low digestibility for protein and energy when un-
treated CSGM is included in its diet (Martínez-Llorens et al., 2012), and the
digestibility decreases with increasing CSGM inclusion level. This phenom-
enon is likely the result of increased ANFs and fibre content. There are many
factors that limit the digestibility of raw materials (Alvira et al., 2010). The
most frequently encountered factors are the processing conditions, the pres-
ence of ANFs, the chemical and physical composition of proteins, and the
fibre content. However, many pre-treatment methods such as autoclaving,
cooking, extruding, fermentation, water-soaking, alkali and acid supplemen-
tation can be employed to partially or completely deactivate some ANFs in
legume seeds (Francis et al., 2001).
The application of heat on legume seeds is necessary for the improve-
ment of its digestibility in rainbow trout possibly due to the inactivation of