Bio-enrichment of oilseed cakes by Mortierella alpina under solid-state fermentation

Oilseed cakes have potential for new applications as substrates for solid-state fermentation (SSF), to increase their nutritional value by increasing its polyunsaturated fatty acids (PUFAs) or protein content. In this sense, it was performed a screening of oilseed cakes to be used as substrates for the production of PUFAs by Mortierella alpina Peyronel MUM 9412. Of all by-products tested, linseed cake (LSC) was the oilseed cake that achieved the highest production of total PUFAs: 153.09 ± 2.25 mg/g. Overall, the PUFAs and protein contents of fermented LSC increased 33% and 11%, respectively. Further, supplementation of the rapeseed cake with linseed oil, prior to the SSF, proved to increase the PUFAs production in about 26%. This study demonstrated the potential of SSF for improving linseed and linseed cakes nutritional composition and the positive effect of linseed oil as inductor to improve the PUFAs production by M. alpina. •Polyunsaturated fatty acids can be produced by solid-state fermentation.•Linseed cake as substrate favor the production of polyunsaturated fatty acids.•Linseed can be enriched in docosahexaenoic acid by solid-state fermentation.•Linseed oil as inductor improved the production of polyunsaturated fatty acids