Reduction of carotenoids in corn gluten meal: Effects on growth performance and muscle pigmentation of rainbow trout (Oncorhynchus mykiss)

Abstract

Saez, P. J., Abdel-Aal, E. M. and Bureau, D. P. 2015. Reduction of carotenoids in corn gluten meal: Effects on growth performance and muscle pigmentation of rainbow trout (Oncorhynchus mykiss). Can. J. Anim. Sci. 95: 79–92. Corn gluten meal (CGM) is an ingredient widely included in aquaculture feeds. The use of significant levels of CGM in diet formulation has been anecdotally related to the suboptimal pigmentation of the muscle of salmonid fish. The results of a few scientific studies that have examined the effect of CGM on muscle pigmentation in salmonids remain inconclusive. Therefore, a bench-scale study was carried out to reduce the content of yellow xanthophyll carotenoids in CGM using white soy flake flour as a bleaching agent. A 12-wk growth trial was then conducted to assess the effects of treated CGM on growth and muscle pigmentation of rainbow trout (Oncorhynchus mykiss) in comparison with regular CGM. Results of the pigment reduction study indicated that the concentration of lutein, zeaxanthin, β-cryptoxanthin and β-carotene was reduced by 86, 97, 100 and 100%, respectively, in the treated CGM. Results of the growth trial showed that the inclusion of treated or regular CGM in the diet did not significantly affect growth performance. However a significant (P<0.05) reduction in astaxanthin deposition was observed in the muscle of fish fed the diet supplemented with 190 g kg−1 of regular CGM when compared with the fish fed the control diet (0 g kg−1 of CGM). The muscle of fish fed the diet containing 190 g kg −1 of treated CGM showed the lowest astaxanthin deposition. This could be attributed to the presence of reactive peroxy radicals produced during the reduction of carotenoids in the treated CGM. Further research is underway to improve the processing method for the reduction of carotenoids in CGM.

Effects of dietary fishmeal substitution with corn gluten meal and poultry meal on growth rate and flesh characteristics of Chinook salmon (Oncorhynchus tshawytscha)

“…Regardless, the low fishmeal diet did not lead to a reduction in total body fat. In salmonids, diets containing corn gluten meal have been associated with reduced concentrations of astaxanthin and the associated red tissue colouration (Saez et al 2014(Saez et al , 2016. Consistent with these findings, in our study the individuals fed the alternative diet that contained corn gluten meal had a significant reduction in tissue redness and tissue astaxanthin levels relative to the fish fed the high fishmeal diet.…”

“…Astaxanthin is the primary carotenoid responsible for this red colouration and is also a major precursor to vitamin A (Anderson 2001;Saez et al 2016). In previous studies of rainbow trout, diets that included plant protein sources, mainly corn gluten meal, were associated with reduced tissue colouration relative to fishmeal diets (Saez et al 2014(Saez et al , 2016. This difference may occur because corn gluten meal contains high levels of yellow xanthophylls (lutein and zeaxanthin; 150-500 mg/kg) (Park et al 1997;Moros et al 2002), which do not impart the same red flesh colouration and could limit astaxanthin uptake due to passive interference during digestion (Furr and Clark 1997;Olsen and Baker 2006).…”

Fillet Quality and Processing Attributes of Postsmolt Atlantic Salmon, Salmo salar, Fed a Fishmeal‐free Diet and a Fishmeal‐based Diet in Recirculation Aquaculture Systems

“…This response is indicative of salmon fillet redness, which is an important quality attribute to consumers and seafood distributors (Alfnes et al ). Some replacement proteins including corn derivatives have been found to negatively impact the fillet color of salmonids (Skonberg et al ; Gatlin et al ; Saez ). Less has been reported regarding the effects on fillet color by other replacement ingredients used in the FMF diet, such as nut meal; however, this study indicates that the ingredient blend used for this FMF diet effectively maintained the red/orange fillet color that is important to salmon consumers (Alfnes et al ).…”