Cottonseed protein concentrate as an alternate protein source for fishmeal replacement in aquafeeds: Production optimisation and its nutritive profile

Abstract

Cottonseed protein concentrates (CPC) was produced from extruded cottonseed meal (CSM) through iso-electric pH precipitation method and the production protocol was optimised for maximum yield of CPC. The processing characteristics such as yield, protein content and key functional properties were investigated. The average yield of CPC obtained was 28.35%. Protein content of CPC was 69.47±1.28% which showed 64.97% increase in protein content of CSM used for production. Amino acid profile of CPC was on par with fishmeal for most of the essential amino acids expect for lysine and methionine. Functional properties such as water holding capacity and oil holding capacity of CPC was not statistically different from fishmeal (p>0.05) and other properties of CPC such as foaming capacity, foaming stability, heat coagulated protein and bulk density were significantly different (p<0.05) from fishmeal. The CPC production process significantly reduced the free gossypol content of CSM to the extent of 79.73% which will help to alleviate the detrimental effects of CSM. Pepsin digestibility of CPC was significantly higher than CSM and slightly lower than FM. The results of this study revealed that CPC could be a suitable alternative protein source feed ingredient for replacement of fishmeal in the diet of marine fishes due to its higher digestible protein, superior amino acid profile and lower gossypol content.

Keywords: Bulk density, Cottonseed protein concentrate, Foaming capacity, Free gossypol content, Pepsin diigestibility