Advanced liquid chromatography/mass spectrometry profiling of anthocyanins in relation to set of red wine varieties certified in Czech Republic.

Hyphenation of micro-liquid and ultra-performance liquid chromatography with a hybrid (QqTOF) tandem mass spectrometry was studied from the viewpoint of their applicability for monitoring of anthocyanin dyes in various cultivars and different vintages of red wine. After appropriate optimization both techniques proved to be suitable for this task. UHPLC system provided lower LOD and LOQ values as well as higher productivity and precision of retention parameters and peak areas with respect to micro-LC method. On the other hand, micro-LC method offers significant savings of mobile phase, less contamination of ion source of mass spectrometer and makes the nebulization process in electrospray much easier. In combination with principal component analysis (PCA), the method allows to elucidate long-term relations in a complete set of certified red wine cultivars grown in South Moravia (certified in Czech Republic until year 2005). Among the studied varieties Rubinet exhibit a specific anthocyanin profile. Especially interesting is a high content of 3-coumaroylglucoside-5-glucosides of malvidin and peonidin. Those dyes can be used as markers of artificial color enhancement. Principal component analysis applied to data processed with regard to enzymatic activity markedly facilitate classification among varieties. This approach allows resolution of teinturiers, variety Blaufränkish and partial classification of other varieties.

Growth of infant faecal bifidobacteria and clostridia on prebiotic oligosaccharides in in vitro conditions.

Our aim was to isolate bifidobacteria and clostridia from infant faeces and to test the growth of bifidobacteria and clostridia on prebiotic oligosaccharides. Seventy breast-fed infants aged between 3 and 253 days were tested for the presence of bifidobacteria and clostridia in their faeces. Ten strains of clostridia and 10 strains of bifidobacteria were isolated from infant faecal samples. Four strains of bifidobacteria originated from culture collections and 1 strain from fermented milk product were also tested. Subsequently, bacterial isolates were tested for their growth on prebiotic oligosaccharides in, in vitro conditions. Forty-six infants exhibited high numbers of bifidobacteria (usually higher than 9 logCFU/g) in their faeces. There were undetectable amounts of bifidobacteria in faecal samples in 24 of the studied infants (34%), these babies on the other hand possessed significant amounts of clostridia in their faecal flora. Both bifidobacteria and clostridia utilized all substrates tested. Bifidobacteria grew significantly better in the medium with galactooligosaccharides. Higher growth of clostridia was observed on raffinose and lactulose. Conversely, bifidobacteria grew slightly better in the medium with stachyose, inulin, Raftilose P85 and P95. However, these differences were not significant. Our results suggest that commercially available prebiotics support the growth of infant faecal clostridia. It is therefore questionable if bifidobacteria-deficient infants should be supplemented with prebiotics.