31.12.2014 Views

here - the 34th European Brewery Convention

here - the 34th European Brewery Convention

here - the 34th European Brewery Convention

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

P91<br />

Screening of brewing yeast strains for development of probiotic craft beers<br />

Dillemans Monique 1 , Van Nedervelde Laurence 1<br />

1 Institut Meurice, Brewing Department, Brussels, Belgium<br />

The aim of this work is to develop new barley malt functional beverages fermented by yeasts with<br />

probiotic physiological properties. Indeed, probiotic cultures have been used as preventive and<br />

<strong>the</strong>rapeutic agent for <strong>the</strong> treatment of diverse digestive diseases. The first selection among 25<br />

industrial brewing yeasts Saccharomyces cerevisia was based on <strong>the</strong>ir gastrointestinal tract tolerance<br />

(acid and basic pH, presence of bile salts and digestive enzymes). The most resistant strains were<br />

tested for <strong>the</strong>ir ability to ad<strong>here</strong> to human cells, <strong>the</strong>ir potential for induction of proinflammatory cytokine<br />

by intestinal cells and o<strong>the</strong>r criteria relevant for any potentially probiotic microorganism. Two<br />

pharmaceutical probiotic yeast strains, Saccharomyces boulardii were used as reference. Among<br />

brewing yeasts tested, three strains have proved <strong>the</strong>ir efficiency for high quality probiotic health beers<br />

production, with acceptable shelf life, depending on alcohol degree and storage temperature.<br />

P92<br />

Reactivation of exhausted yeast physiological activity<br />

Mario Novak 1 , Filip Cingesar 1 , Zvonko Petrović 2 , Philippe Cario 3 , Božidar Šantek 1<br />

1 University of Zagreb, Faculty of Food Technology and Biotechnology, Department of Biochemical<br />

Engineering, Zagreb, Croatia, 2 Ireks Aroma d.o.o, Zagreb, Croatia, 3 AEB SPA, Brescia, Italy<br />

Aims: The aim of this research was to prolong <strong>the</strong> yeast re-pitching process without loosing beer<br />

quality.<br />

Methods: In this research lager yeast (5 th generation stored at + 4 o C for 5 days) was used for wort<br />

fermentation w<strong>here</strong> yeast properties and metabolites concentrations were monitored. In order to<br />

reactivate yeast activity different nutrients mixtures (amino-acids, peptides, proteins, vitamins and<br />

minerals) were prepared.<br />

Results: The use of inorganic or organic nutrients mixtures insures that fermentation will be<br />

successfully completed compared to <strong>the</strong> fermentation without nutrients mixture. The use of organic<br />

nutrients mixture resulted in <strong>the</strong> increase of yeast concentration and in <strong>the</strong> reactivation of fermentation<br />

process. Reactivated yeast was also capable to perform a few more fermentations.<br />

Conclusions: The use of organic nutrients mixture can significantly improve exhausted yeast activity<br />

and to reactivate declined fermentation without considerable impact on <strong>the</strong> beer quality.<br />

P93<br />

Evaluation of Near-Infrared Spectroscopy (NIRS) for on-line determination of critical process<br />

parameters for fermentation process control<br />

Lucas Vann 1 , Johnathon B Layfield 1 , John D Sheppard 1<br />

1 North Carolina State University, Food, Bioprocessing & Nutrition Sciences, Raleigh, United States<br />

The search for improved methods for process control has led to <strong>the</strong> development and application of<br />

Near-Infrared Spectroscopy (NIRS). NIRS can be implemented in real-time with several<br />

determinations being made simultaneously from a single spectral scan t<strong>here</strong>by maximizing process<br />

monitoring and control capabilities. The present research explores its potential for on-line fermentation<br />

monitoring of specific gravity (SG), free amino nitrogen (FAN) and percent alcohol by volume (% EtOH<br />

v/v) for <strong>the</strong> purpose of control of fermentation rate and maturation time. Pilot-scale batch model

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!