Applications of plant ingredients for tropical and subtropical freshwater finfish: possibilities and challenges

The demand for cultured finfish has increased tremendously during the last decades, but the success of intensive farming is dependent on several factors, namely management, dietary supplementations and welfare. During the last decades, increasing demand, high price and limited supply of fishmeal have emphasized the need for alternative protein sources in aquafeeds, but plant proteins possess a series of endogenous antinutritional factors (ANFs; e.g. protease inhibitors, tannin, mimosine, phytic acid, nonstarch polysaccharides), and they must be destroyed or inactivated. Inclusion of alternative protein sources has resulted in production losses and is a concern for farmers. However, the problem with ANFs might be solved using advanced processing techniques. The present review, focusing on tropical and subtropical freshwater finfish, will discuss findings on applications of conventional methods, as well as fermentation technology for deactivation of endogenous ANFs, and the use of probiotics with ANF degrading potential when plant ingredients are included in fish feeds.