Biomedical subjects

Filip Delvaux

Publications and source records attributed to Filip Delvaux.

3 recordsLinked to original sources

PubMed2006

Determination of hydroxycinnamic acids and volatile phenols in wort and beer by isocratic high-performance liquid chromatography using electrochemical detection.

The suitability of a simple and rapid isocratic RP-HPLC method with amperometric electrochemical detection for the simultaneous detection and quantification of hydroxycinnamic acids and their corresponding aroma-active volatile phenols in wort and beer is reported. The technique gives good specificity and sensitivity, and can therefore be used for routine monitoring of hydroxycinnamic acids in wort and the development of volatile phenolic flavour compounds during the beer production process and subsequent conservation.

Beer↗

PubMed2006

Immobilized yeast cell systems for continuous fermentation applications.

In several yeast-related industries, continuous fermentation systems offer important economical advantages in comparison with traditional systems. Fermentation rates are significantly improved, especially when continuous fermentation is combined with cell immobilization techniques to increase the yeast concentration in the fermentor. Hence the technique holds a great promise for the efficient production of fermented beverages, such as beer, wine and cider as well as bio-ethanol. However, there are some important pitfalls, and few industrial-scale continuous systems have been implemented. Here, we first review the various cell immobilization techniques and reactor setups. Then, the impact of immobilization on cell physiology and fermentation performance is discussed. In a last part, we focus on the practical use of continuous fermentation and cell immobilization systems for beer production.

Beer↗

PubMed2004

Ferulic acid release and 4-vinylguaiacol formation during brewing and fermentation: indications for feruloyl esterase activity in Saccharomyces cerevisiae.

The release of ferulic acid and the subsequent thermal or enzymatic decarboxylation to 4-vinylguaiacol are inherent to the beer production process. Phenolic, medicinal, or clove-like flavors originating from 4-vinylguaiacol frequently occur in beer made with wheat or wheat malt. To evaluate the release of ferulic acid and the transformation to 4-vinylguaiacol, beer was brewed with different proportions of barley malt, wheat, and wheat malt. Ferulic acid as well as 4-vinylguaiacol levels were determined by HPLC at several stages of the beer production process. During brewing, ferulic acid was released at the initial mashing phase, whereas moderate levels of 4-vinylguaiacol were formed by wort boiling. Higher levels of the phenolic flavor compound were produced during fermentations with brewery yeast strains of the Pof(+) phenotype. In beer made with barley malt, ferulic acid was mainly released during the brewing process. Conversely, 60-90% of ferulic acid in wheat or wheat malt beer was hydrolyzed during fermentation, causing higher 4-vinylguaiacol levels in these beers. As cereal enzymes are most likely inactivated during wort boiling, the additional release of ferulic acid during fermentation suggests the activity of feruloyl esterases produced by brewer's yeast.

Beer↗