Download SIP - Leaf-like rest streams - 20150317

Biorefinery of leaf material
(part of the research line Biorefinery of protein-rich biomass)
Background
Materials like grasses duckweed leaves are agro-feedstocks that people have recognized as an
important future source of protein. Research programmes at TNO and DLO-FBR have been defined to
make maximum use of the protein’s technical functionalities in food/feed applications. A good example
are the 5 running projects in the STW-Protein programme. Possibilities for the combined applications of
protein / -fractions in both food/feed and chemical industry have so far been underexplored. It is the
ambition of the present research line to address this issue in close collaboration with industrial partners.
The chemical applications studied so far are mostly based on the hydrolysis of the proteins into amino
acids followed by fractionation and separation. However, this procedure also implies that most of the
inherently available and useful functionalities are lost, thereby reducing the intrinsic quality and value of
the proteins. In particular the membrane protein fractions have functionalities which could be of great
interest for the chemicals and materials industry. As they are both hydrophilic and hydrophobic,
membrane proteins have surface active properties. They can, therefore, be used as emulsifiers in paints
and cosmetics, as adhesives in the paper industry, as well as water binder in numerous other
applications.
Intended effects
At TNO and DLO-FBR, much knowledge has already been developed on soluble proteins from leaves in
general, and of Rubisco in particular. Applications have so far mainly focussed on food/feed outlets.
Within this research line we aim to (co-) produce proteins from leaves for chemical and material
applications that are complementary to food/feed applications. The valorisation of membrane proteins
will aid the biorefinery concept of leaves and will increase its economic viability.
Research focus
TNO and DLO-FBR will combine their technology portfolios to develop a biorefinery concept that delivers
chemical and material applications of proteins which are complementary to food/feed applications. Topics
that will be investigated in more detail are:
•
Biomass deterioration. Leaves that are harvested need to be processed to avoid chemical (e.g.
reaction with polyphenols), enzymatic (e.g. proteolysis) or microbial degradation. When do these
processes occur? And how to avoid them? Can silage be used?
•
Pre-treatment technology. Which technology can best be used to open the cells? Is a mechanical
treatment preferred? Can Pulsed electric field be used as a method that combines preservation and
disruption?
•
Protein technology. Can we isolate and characterise membrane protein from interesting leaf sources?
Can we find technologies to separate the membrane protein/lipid complexes that still occur?
•
Modifications. The obtained protein fraction may have interesting properties as such. However, it
may be further improved to better meet certain applications. Can we e.g. modify the proteins to
either solubilize them in water or make them even more hydrophobic? Can we use (partial)
hydrolysis to convert them into peptides and amino acids? Can we separate these fractions for
different applications?
•
Polyphenols. In many cases polyphenols are a hindrance, reacting with protein and causing browning
of the product. Can polyphenols be used to our advantage; either as (part of) a product, or by
hydrophobising the protein to get better material properties?
•
Application. Membrane proteins can be obtained in the same process that isolates Rubisco. Food
applications are investigated within the STW Protein programme. Here, sometimes colour and smell
are a hindrance that may not be a problem in other applications. What are the options for non-food
applications? Does the protein need to be decolorized and/or delipidized? Which further modifications
are required to meet the requirements for broader application?
•
Biorefinery. Can we combine protein valorisation with the production of other products like
polyphenols and carbohydrates (e.g. pectin)?
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•
Scaling. Leaves are generally very high in water content. Can small scale processing be used to get
fast preservation, local recycling of water and minerals, lower transportation cost, and in this specific
case: a better quality product?
Examples of biomass sources that can be used for this purpose include:
•
, Luzerne, grass, tea leaves or other leaves.
•
Grass: Within the Netherlands, about 10.5 Mton dry matter per year is being produced from 1 Mha of
cultivated grassland. This is exclusively used as fresh or preserved feed for cattle, sheep, goats and
horses.
Duration/planning
The project will initially have a duration of 2 years; the period for which funding from EZ for TNO and
FBR is available. Both TNO and FBR strive to continue the project after this period.
Invitation to Industrial Partners
Industrial parties interested and able to act as suppliers or converters of (sidestream) proteins, potential
producers and users of protein derived products, are invited to join the project.
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