It was shown that upscaling with respect to screw pressing had same efficiency independent of scale, while the protein separation in both Pilot Plant and semi-large scale production performed less efficient and lower than the theoretical yield compared to lab scale yield. Thus there is a focus area for further improvements.
Protease treatment of green biomass screw press pulp resulted in Rubisco protein hydrolysate. Amino acid analysis suggest this to have interesting and scalable potentials as both feed and food ingredients. (NB the Rubisco protein hydrolysate from green biomass screw press pulp has not yet been included in the feeding trials).
The dairy cattle feeding experiment with 36 cows is expected to be reported in Q3 2017.
Preliminary conclusions: It is estimated that by the present technology for bio-refining 45% of the protein present in the green biomass can be recovered in a protein concentrate paste having protein content in the range of 47% of dry matter; almost similar to the protein content of soybean meal. In addition a fibre fraction containing 17% protein in dry matter can be produced and used for ruminant feed, energy production or further bio-refined into chemical blocks or used for bio-materials. Part of this fiber fraction can further be processed into other compounds with added value i.e. oligosaccharides. Project 2 has demonstrated positive prebiotic effect of Xylo-oligosaccharides (XOS) from wheat straw and of XOS from rye grass.
Much of the additional knowledge gathered in Project 2 is included in the report “Green biomass – protein production through bio-refining”, commissioned by the Ministry of Environment and Food.