Characterization and fate of black currant and bilberry flavonols in enzyme-aided processing.
The fate of black currant ( Ribes nigrum L.) and bilberry ( Vaccinium myrtillus L.) flavonols in enzyme-aided processing was studied. The flavonols were quantified and characterized by high-performance liquid chromatography equipped with a diode array detector and an electrospray ionization mass spectrometer. A tentative identification for 14 black currant and 19 bilberry flavonols is presented representing 11 previously unpublished conjugates. For the first time in any berry, the presence of laricitrin conjugates is reported. The enzyme-aided processing affected the flavonol extractability, elevating the yield in juices and decreasing that in press residues. Importantly, no significant loss of the berry flavonols was observed during the experiments, although some hydrolysis of flavonol conjugates was recorded. To maximize the effect on flavonol extractability, higher enzyme dosages were needed for black currants than for bilberries. The data show that the flavonol extractability and hydrolysis are dependent on the texture of raw material, the glycosylation pattern of the conjugates, and the activity profile of the enzyme preparation.
Koponen
Jani M
JM
Food and Health Research Centre, Department of Clinical Nutrition, and Department of Pharmaceutical Chemistry, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland. Jani.Koponen@ktl.fi
Happonen
Anu M
AM
Auriola
Seppo
S
Kontkanen
Hanna
H
Buchert
Johanna
J
Poutanen
Kaisa S
KS
Törrönen
A Riitta
AR
D001628:Beverages / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D011096:Polygalacturonase; D031965:Ribes / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D029800:Vaccinium myrtillus / Q000737:chemistry*
D044948:Flavonols; D011096:Polygalacturonase