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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).

 


VTT Technical Research Centre of Finland

VTT Biotechnology


 

 

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