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New
CROSSENZ partners in a meeting in Nauvo, Finland, June
2004
Progress in the
CROSSENZ project during the first period
The project has commenced by preparation of suitable protein
and carbohydrate model substrates and raw materials for the enzymatic
modification studies. Various phenolic carbohydrates, i.e. pectins and
arabinoxylans were selected from commercial sources or produced specifically
for the project. The mechanistic part of this project has been started with
commercially available enzymes, or with the enzymes available from partners.
Besides phenolic carbohydrates, different proteins were also selected from
commercial sources and tested for their crosslinking ability with
transglutaminase as well as different oxidative enzymes.
Discovery of novel enzymes is carried out
and the screening work has been divided with three partners, each focusing
its own speciality: microbial enzymes, plant enzymes and non-GMO enzyme
production systems. Also other types of potential cross-linking enzymes have
been identified and their suitability for cross-linking on both protein and
carbohydrate based materials is being explored. During the first year
interesting oxidative enzymes, e.g. a novel fungal tyrosinase (Halaouli
et al, 2005) have been
isolated and
characterized Plant based oxidative enzymes have also been isolated and
their biochemical properties have been compared to the microbial ones. The
production of the enzymes in heterologous host organisms is carried out
using filamentous fungi and plant expression systems. In parallel a non-GMO
approach is developed. The rationale is to evaluate and compare the
efficiency and also consumer acceptance of alternative production methods.
The enzymatic cross-linking is studied using both protein and
carbohydrate polymers and their model structures using advanced analytical
techniques. The essential analytical techniques for crosslinking analysis
are: LC-MS, MALDI-TOFF, ESR, HPLC, NMR, and FTIR. During the first period
the impact of the feruloylation degree on the
structure and properties of arabinoxylan
gels has been elucidated (Carvajal-Millan
et al., 2005). Also the kinetics of transglutaminase-induced
cross-linking of wheat proteins in dough has been
investigated (Autio
et al, 2005). The knowledge obtained will be exploited in
application development for meat, dairy and bakery products.
Consumer
studies have provided an interesting asset for enzyme development work.
It could be concluded that attitudes towards use of enzymes in food
production are fairly neutral, whereas attitudes towards use of gene
technology in food production and towards enzymes produced by use of gene
technology are more negative. Respondents in Germany are more positive
towards enzymes in food production than respondents in Finland and Italy.
Results also showed that more knowledge about enzymes leads to a more
positive attitude, except in Germany.
Consumers had a
slight preference to plant based enzymes instead of microbially produced
enzymes and this might give indication for enzyme producers also to look
even more carefully this alternative (Alsted
Søndergaard et al, 2005;
consumer corner).
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VTT
Biotechnology
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