Background: Rapeseed cake is a good source of protein for animal feed but its utilization is limited due to the
presence of anti-nutritional substances, such as glucosinolates (Gls), phytic acid, tannins etc. In the present study, a
solid state fermentation (SSF) using Aspergillus niger was carried out with the purpose of degrading glucosinolates
and improving the nutritional quality of rapeseed cake (RSC). The effects of medium composition and incubation
conditions on the Gls content in fermented rapeseed cake (FRSC) were investigated, and chemical composition and
amino acid in vitro digestibility of RSC substrate fermented under optimal conditions were determined.