Enrichment of a Plant Feedstuff Mixture's Nutritional Value through Solid-State Fermentation.

Simple Summary: Sustainable animal nutrition and feeding are critical to meeting the growing population's food needs, requiring more resource-efficient feed production with less waste. This work aims at the nutritional valorization of plant feedstuffs using one of the most ecological, inexpensive, and convenient large-scale industrial and technological treatments, as well as solid-state fermentation. Fermentation proved useful in adding value-added compounds to the plant feedstuffs as proteins and enzymes, increasing protein digestibility, and reducing fiber, creating a novel feedstuff that could help reduce waste and the use of unsustainable ingredients when applied to animal nutrition. Plant feedstuffs are the main ingredients of animal feed. Owing to food–feed competition, increasing the utilization efficiency of these feedstuffs is important for animal nutrition. This can be achieved via solid-state fermentation (SSF). SSF of a plant feedstuff mixture (PFM) (25% rapeseed meal, soybean meal, rice bran, and sunflower meal) by three fungi (Aspergillus ibericus MUM 03.29, Aspergillus niger CECT 2088, and Aspergillus niger CECT 2915) resulted in an increase in protein content by 5%, irrespective of fungi, a reduction in cellulose content by 9 to 11%, and of hemicellulose content by 21 to 34%, relative to unfermented PFM. Enzyme production was measured: the highest cellulase (123.7 U/g), xylanase (431.8 U/g), and beta-glucosidase (117.9 U/g) activity were achieved with A. niger CECT 2088. Principal component analysis showed a positive correlation between all fermented PFMs and enzyme production, protein content, digestibility, and fiber reduction. Bioprocessing of the PFM by SSF increased its nutritional value and digestibility, making it more appealing for animal feeds. [ABSTRACT FROM AUTHOR]