The potential for biorefining of triticale to protein and sugar depends on nitrogen supply and harvest time

Biorefining of green biomasses to produce proteins for feed and food along with fibers/sugars for production of fuels and chemicals constitutes one viable pathway in the transition to a bio-economy. In this respect, maximizing annual biomass output is a key parameter and one potential new concept could be green harvest of cereal crops followed by early establishment of a cover crop. The objective of this study was to evaluate different scenarios for harvesting and biorefining triticale either at maturity or earlier in green growth stages. High-yielding triticale was grown under different regimes of N-application and was harvested at three stages of maturity from green to full maturity. Green biomass was fractionated into a fiber rich pulp and a protein rich juice, from which a protein concentrate was produced. The digestibility and sugar potential of the fiber pulp was evaluated against mature straw by enzymatic hydrolysis after hydrothermal pretreatment. Triticale biomass and protein yield did not increase during the last 5–6 weeks before harvest at maturity in August. On average 21 t ha−1 of dry weight biomass was harvested in early July. Fractionation of protein from the green triticale resulted in the production of 730 kg ha−1 of crude protein in a protein concentrate with an amino acid profile superior to grain protein. The structural carbohydrates in the green biomass and the fiber pulp were less recalcitrant compared to mature straw. The total sugar potential from biorefining of green triticale was under the given conditions up to 5.3 t ha−1.