Enhancing protein recovery in green biorefineries through selection of plant species and time of harvest

Abstract Biorefining is a promising method for sustainable feed production through conversion of biomass into a protein concentrate for monogastrics and fibrous pulp for ruminants. Nitrogen (N) content and recovery in pulp and protein concentrate from lucerne, red clover, white clover, perennial ryegrass and tall fescue harvested at different spring cut harvest times were analysed to assess the effect of plant species, developmental stage and number of screw press processing. Plant species and spring cut harvest time affected N content of pulps and protein concentrates (P  The N content and recovery in fractions produced in the biorefining process were dynamic variables influenced by plant species, spring cut harvest time and number of screw press processings. More N was retained in the pulp from late cut grasses whereas the N recovery in protein concentrate was highest in early and intermediate cuts from legumes. The dynamics of N distribution between pulp and protein concentrate highlight the importance of considering input plant species, time of harvest and processing technique in order to enhance recovery and secure efficient utilisation of the biomass as feed for monogastrics and ruminants.