The impact of the matrix of red beet products and interindividual variability on betacyanins bioavailability in humans.

The influence of the matrix of red beetroot products and interindividual variability on betacyanins bioavailability in humans was studied. In a randomized crossover study 12 volunteers consumed red beet juice and crunchy slices containing betanin and isobetanin. Betalains were analyzed by the HPLC-DAD-MS. Urine samples examined after the consumption of both products contained not only native betacyanins but also their aglycones. In case of juice, the highest betacyanins urine excretion rate was observed within the first 2 h (64 nmol/h), while in case of crunchy slices within the period of 2-4 h (66 nmol/h). Among volunteers, the average total betacyanins excretion rate ranged from 18.54 to 67.96 nmol/h and, 13.15 to 63.58 nmol/h for red beet juice and crunchy slices, respectively. In total, approximately 0.3% of betacyanins (ranging from 0.12 to 0.58%) ingested from both products was excreted. The study showed that betacyanins bioavailability from juice and crunchy slices is similar, with the matrix of products consumed having an impact on betacyanins excretion profile, and the phenotype of volunteers affecting betacyanins excretion rate.

Profile and Content of Betalains in Plasma and Urine of Volunteers after Long-Term Exposure to Fermented Red Beet Juice.

The aim of this study was to determine profile and content of betalains in volunteers' plasma and urine after long-term exposure to fermented red beet juice. During 6 weeks, 24 healthy volunteers consumed juice with a dose of 0.7 mg betalains/kg body weight. Betalains were analyzed by means of micro-HPLC-MS/MS. Twelve betalain derivatives were found in blood plasma and urine after juice intake. The highest betalains level in blood plasma (87.65 ± 15.71 nmol/L) and urine (1.14 ± 0.12 µmol) was found after the first and second week of juice intake, respectively. During juice consumption, the contribution of betalain metabolites was higher than that of native betalains, and interindividual variability in profile and content of betalains was observed. Summarizing, it was observed that long-term and regular consumption of the juice causes stabilization of profile and content of betalains in physiological fluids of volunteers, which include native compounds and their decarboxylated and dehydrogenated metabolites.

Bioavailability of cyanidin glycosides from natural chokeberry (Aronia melanocarpa) juice with dietary-relevant dose of anthocyanins in humans.

The aim of this study was to investigate the bioavailability of anthocyanins from chokeberry juice with a dietary-relevant dose of anthocyanins. Thirteen healthy volunteers consumed chokeberry juice providing 0.8 mg of anthocyanins/kg of body weight. Before and after juice consumption, blood and urine were collected. Concentration of anthocyanins was measured with HPLC-PDA-MS-ESI. Cyanidin-3-galactoside comprised 66% of total chokeberry anthocyanins. Eight cyanidin derivatives were found in blood and urine after juice consumption. The maximum plasma anthocyanin concentration of 32.7 ± 2.9 nmol/L was reached at 1.3 ± 0.1 h after juice consumption. The anthocyanins' urine excretion rate (62.9 ± 5.0 nmol/h) was the highest within the first 2 h. In total, 0.25 ± 0.02% of the ingested anthocyanins was excreted by the renal route during 24 h, mainly as metabolites of cyanidin. According to these observations, after consumption of a dietary-relevant dose of anthocyanins as natural chokeberry juice, anthocyanins and their metabolites were present in plasma and urine of volunteers.