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Our vision of exopolysaccharides

Exopolysaccharides (EPS) are not only sticky stuff produced from saccharose. They serve many functions for the producing bacteria as well as for food structure and human (functional) nutrition. An EPS pruducer not only differs from the non-producer by slime production but changes multiple pathways in its metabolism as a result of a changed redox balance, e. g. upon metabolizing fructose serving as electron acceptor. EPS and/or the cell wall bound glycosyltransferases responsible in their formation may also help it to better survive desiccation or intestinal passages. Specific EPSs/glycosyltransferases may also aid in pathogen prevention by blocking receptor sites in the intestinal mucosa.

Applied in food as purified compounds or via in situ production by starter cultures they are natural texturants, e. g. improving water binding capacity, machineability and elasticity of bread doughs as well as volume and crumb structure of breads. In milk products they are widely applied to produce attractive mounthfeel and creamy structures.

Depending on their specific molecular structure EPSs, namely fructans and fructooligosaccharides can also feed specific bacteria (e. g. Bifidobacteria) in the gut and are therefore suggested for use as pre- and synbiotics.

EPSs research is one of our long term topics and the "sticky glue" between a variety of our projects listed in different categories.

 




Development of exopolysaccharide-producing starter cultures for meat products

The use of exopolysaccharides (EPS) is widely unexplored in meat products. Putative advantages of in-situ produced EPS include improved coherence of meat particles and fat replacement/reduction. In this project it is intended to (i) demonstrate the correlation between the EPS formation and stress responses in meat matrices, (ii) demonstrate the correlation between fermentation and formation conditions of EPS and their macromolecular structure, and (iii) establish correlations between the macromolecular structure of EPS and the quality of meat products. These results will have a number of positive economic benefits for participating industries including starter culture companies and meat manufacturing industries. Our results will enable the companies to enlarge their product portfolio (e.g. clean labeled meat products). New product innovations could be expected due to in-situ EPS formation.

project leader: Rudi F. Vogel / Frank Jakob

participating scientists: Roman Prechtl

open positions: none

cooperations: Jochen Weiss, Myriam Löffler (www.uni-hohenheim.de)

 


 

 

Innovative additives with microbial exopolysaccharides for physicochemical stabilization of turbid beverages

A new generation of techno-functional additives is developed with turbidity stabilizing, emulsifying properties and attractive sensorics upon exploitation of exopolysaccharide (EPS) producing strains of lactic acid bacteria, which are adapted to sucrose-containing substrates or are used for the production of traditional bevaerages like water kefir or kombucha. As a result of the variation of strains and fermentation parameters EPS are obtained, which differ in amount, macromolecular size and functionality. These properties are related to beverage specific requirements namely turbidity stabilization and emulsifying properties to enable a knowledge based kolloidal stabilization of beverages and other foods.

project leader: Rudi F. Vogel / Frank Jakob

participating scientists: Julia Bechtner, Viktor Eckel

open positions: none

cooperations: Jan Schneider (www.hs-owl.de)

 


 

 

Exploitation of in situ produced exopolysaccharides for the structural improvement of fermented lupin based alternatives to yoghurt

A new generation of fermented, vegan yoghurt alternatives is developed with a deliberately designed spectrum of structures and attractive sensorics upon exploitation of exopolysaccharide (EPS) producing strains od lactic acid bacteria, which are adapted to the fermentation of leguminoses. Producers are characterized, which deliver homo- or heteropolysaccharides with varying macromolecular sizes and structure forming properties. The correlation of these EPS properties with the structure forming properites in the lupin based yoghurt alternatives enables targeted product development.

project leader: Rudi F. Vogel / Frank Jakob

participating scientists: Jonas Schmid

open positions: none

cooperations: Ute Weisz, Andrea Hikisch (www.ivv.fraunhofer.de)

 


 

 

Exploitation of bacterial ß-glucans for the structural and nutritional improvement of bakery products

 

The aim of this study is the development of application-oriented basics for the knowledge-based use of ?-glucan-producing lactic acid bacteria species for the improvement of the nutritional and structural value of bakery products. The central hypothesis is that dough from rye and wheat which are naturally poor in ?-glucan can be enriched in ?-glucan by adjustable sourdough fermentation using specific glucan-producing lactic acid bacteria species. This soluble dietary fiber could exibit cholesterol-reducing and chemopreventive as well as structuring properties similar to cereal or other glucans.

 

project leader: Frank Jakob

participating scientists: Julia Bockwoldt, Matthias Ehrmann

open positions: a PhD position. is open from december 2018

cooperations: none