Preliminary assessment of a novel fermented wheat protein concentrate from a bio-distillation source as a dietary ingredient contribution for tilapia (Oreochromis niloticus)

Abstract

A novel technologically advanced fermented wheat gluten and yeast sourced protein (FWPC) co-product utilising Saccharomyces cerevivisiae yeast was evaluated for juvenile Nile tilapia Oreochromis niloticus. The protein component of a semi-purified basal diet (control treatment) was incrementally replaced by Fermented Wheat Protein Concentrate (FWPC) at 10%, 20%, and 30% of total dietary protein to create a slope-assay response to the test ingredient compared to an ‘ideal protein’ essential amino acid EAA balanced source. After an 8-week feeding trial, tilapia fed 10% and 20% FWPC displayed similar performance to those fed the control FM based diet, while fish fed 30% FWPC gave the lowest growth performance (P ≤ 0.05) compared to the other treatments. Proximate composition analysis showed that body protein, lipid, ash, NFE and gross energy were unaffected by dietary treatment (P ≥ 0.05). Both plasma alanine aminotranferase (ALAT) and aspartate aminotranferase (ASAT) were measured as indicators of hepatic function in Nile tilapia. No effects were seen in ALAT and ASAT activities. Tilapia fed 30% FWPC showed reduced HSI (P ≤ 0.05) compared to the other treatments. Additionally, histological comparisons of liver and intestinal tissues gave no indication of impairment to health, but FWPC inclusion elevated the number of goblet cells present in the posterior intestine (P ≤ 0.05). Ultrastructure of microvilli height and density also increased significantly showing functional aspects of FWPC. This study reveals the potential benefits of utilising a potable alcohol derived FWPC on the growth and feed utilisation performance of Nile tilapia, with no apparent adverse impacts on general health and physiological status as determined by gut and liver function and related plasma metabolic status. The results are discussed in the context of a promising protein ingredients source for tropical fish aquaculture.