Applicability of ultra performance convergence chromatography, a new generation of supercritical fluid chromatography, for the analysis of pesticide residues

Monitoring and controlling wide variety of pesticide residues is a crucial challenge of food safety. In our study ultra-performance convergent chromatography (UPC2), as the new generation of supercritical fluid chromatography coupled with ESI-MS/MS system was applied to separate a set of pesticides to investigate their chromatographic behavior under various UPC2 conditions. 30 components were selected representing the GC and LC measurable components. Capacity factors obtained from LC and GC runs UPC2-PDA were compared. Based on our data UPC2 should be considered as an alternative chromatographic approach with separation mechanisms not yet fully characterized. Interestingly the type of mobile phase modifier influences the ionization in an ESI-MS system

Effects of food processing technology on valuable compounds in elderberry (Sambucus nigra L.) varieties

Elderberry (Sambucus nigra L.) is a potential source of natural food colorants because of its high anthocyanin content. The aim of this work is to reveal which technology step has effect on the valuable components (total anthocyanins, total polyphenols) and on the color parameters in elderberry and in this regard to determine possible differences between elderberry varieties. Based on experiment results concentrate production steps have great effects on the studied parameters in case of two varieties especially in the heating and microfiltration steps but in different ratio. Polyphenolic compounds in ‘Samocco’ are more stable during the juice production than ‘Haschberg’. Color stability test revealed that in case of colored samples ‘Samocco’ had stronger color intensity in the foods/ models. These differences should be taken into account when selecting a certain variety for industrial utilization

Genistein isoflavone glycoconjugates in sour cherry cultivars : Prunus cerasus L.

Although the isoflavone genistein has well-established health-beneficial effects, it is not a major component of Western diet, since soy consumption, the main dietary source of genistein, is low in these populations. Genistein compounds were studied in twelve commercial sour cherry (Prunus cerasus L.) cultivars grown in Hungary. High performance liquid chromatography coupled to quadrupole/time-of-flight mass spectrometry, equipped with electrospray ion source (HPLC-ESI-qTOFMS) was used for screening and confirmatory analyses. Genistin and genistein were found in some Hungarian native sour cherry cultivars including ‘Pipacs1’, ‘Kántorjánosi’, ‘Debreceni bőtermő’ and ‘Éva’. Genistein content in fruits of the latter three cultivars ranged between 0.4 to 0.6 mg, while in ‘Pipacs1’ a total of 4.4 mg genistein compounds (expressed as aglycone equivalents per 100 g of fresh fruit) was determined. These cultivars may play an important role as complementary genistein sources in the Western diet. Especially ‘Pipacs 1’, may be best utilized in functional food products

Conversion of rutin, a prevalent dietary flavonol, by the human gut microbiota

The gut microbiota plays a pivotal role in the conversion of dietary flavonoids, which can affect their bioavailability and bioactivity and thereby their health-promoting properties. The ability of flavonoids to stimulate the activity of the microbiota has, however, not been systematically evaluated. In the present study, we used a fluorescence-based single-cell activity measure [biorthogonal non-canonical ammino acid-tagging (BONCAT)] combined with fluorescence-activated cell-sorting (FACS) to determine which microorganisms are stimulated by the flavonoid rutin. We performed anaerobic incubations of human fecal microbiota amended with rutin and in the presence of the cellular activity marker L-Azidohomoalanine (AHA) to detect rutin-stimulated cells. We found that 7% of cells in the gut microbiota were active after a 6 h incubation and 23% after 24 h. We then sorted BONCAT-positive cells and observed an enrichment of Lachnospiraceae (Lachnoclostridium, and Eisenbergiella), Enterobacteriaceae, Tannerellaceae and Erysipelotrichaceae species in the rutin-responsive fraction of the microbiota. There was marked inter-individual variability in the appearance of rutin conversion products after incubation with rutin. Consistent with this, there was substantial variability in the abundance of rutin-responsive microbiota among different individuals. Specifically, we observed that Enterobacteriaceae were associated with conversion of rutin into quercetin-3-glucoside and Lachnospiraceae were associated with quercetin production. This suggests that individual microbiotas differ in their ability to metabolize rutin and utilize different conversion pathways