Activity: Talks and presentations › Talks and presentations in private or public companies
Various compounds of the flavonoid group have been reported to possess therapeutic effects towards cancer . Thus there is a large potential in identifying, purifying and quantifying flavonoids from different natural sources in order to screen the pharmaceutical values of these. The flavonoids are normally present in much smaller quantities than other solutes such as sugars and organic acids. This may state a problem in analysis as some of the flavonoids are present in very minute amounts and concentration is limited by the major solutes. This study seeks to separate the sugars and organic acids from the flavonoids in order to facilitate better analysis. In the current study, the major solutes in black currant juice are fructose (32 ± 3 g/l), glucose (22 ± 3 g/l), sucrose (1.6 ± 0.2 g/l) and organic acids (28.9 ± 0.1 g/l). The flavonoids in black currant juice are mainly (97%) comprised by the glucosides and rutinosides of cyanidin and delphinidin . The content of these flavonoids in black currant juice is measured to (1.5 ± 0.1 g/l). The separation process consists of nanodiafiltration on flat sheet membranes with a nominal molecular weight cut off of 1,000 Da. The separation process was monitored by comparing concentrations of the four flavonoids and the sugars and acids in permeate and retentate. The flavonoids in the juice have a molecular weight between 449 and 611 Da and should be able to pass the pores of the membrane. However this study shows that the flavonoids is mainly kept in the retentate where as fructose (180 Da), glucose (180 Da) and sucrose (342 Da) are gradually flushed out into the permeate. By diafiltration, it was possible to remove almost all glucose and fructose from the juice. The weight percentage of the flavonoids on dry weight basis increased from 1% to 44 % during the separation process.
 F. Teillet, A. Boumendjel, J. Boutonnat, X. Ronot, Flavonoids as RTK Inhibitors and Potential Anticancer Agents, Medicinal Research Reviews, 2008, 28(5), 715-745
 M.J. Anttonen, R.O. Karjalainen, High-Performance Liquid Chromatography Analysis of Black Currant (Ribes nigrum L.) Fruit Phenolics Grown either Conventionally or Organically, Journal of Agricultural and Food Chemistry, 2006, 54, 7530-7538
Emneord: Flavonoid, Anthocyanin, Nanofiltration, Diafiltration, Black Currant