Bioavailability of ß-cryptoxanthin in the presence of phytosterols: in vitro and in vivo studies.

Bioactive compounds are used in the design and development of new food products with potential health benefits, although little is known regarding their bioavailability and interactions. This study assessed the stability, in vitro bioaccessibility, and human bioavailability of ß-cryptoxanthin from ß-cryptoxanthin-rich drinks with and without added phytosterols developed for this purpose. The developed drinks showed no difference in the content of ß-cryptoxanthin, and they were stable over 6 months. In vitro, hydrolysis of ß-cryptoxanthin esters and the amount of free ß-cryptoxanthin at duodenal and micellar phases were similar regardless of the presence of phytosterols. In the human study, the daily intake provoked significant increments of ß-cryptoxanthin in serum regardless of the type of the drink. In conclusion, in vitro and in vivo human studies have shown that the bioavailability of ß-cryptoxanthin is not significantly affected by the presence of phytosterols when they are simultaneously supplied in a drink.

Depletion of serum carotenoid and other fat-soluble vitamin concentrations following obesity surgery.

BACKGROUND: Obesity constitutes a growing health problem, and surgical treatment of severe obesity is increasingly used. Nutrient deficiencies are common following bariatric surgery and the evidence indicates a progressive increase in the incidence and severity of the deficiency of certain vitamins and related clinical conditions. Because of the potential role of carotenoids in disease prevention, our aim was to assess the carotenoid status in candidates for obesity surgery and the time-course changes following two bariatric procedures. METHODS: Seventy-five candidates for bariatric surgery (17 men, 58 women; age 43 ± 10 years) and a total of 362 serum samples after obesity surgery (i.e., Roux-en-Y gastric bypass (n = 187) and biliopancreatic diversion (n = 175)) were consecutively collected and assessed. Retinol, α- and γ-tocopherol, 25-OH-vitamin D3, lutein, zeaxanthin, α- and ß-cryptoxanthin, lycopene (trans and cis), α- and ß-carotene (trans and cis) were analyzed by high-performance liquid chromatography. RESULTS: Mean serum levels of carotenoids in candidates for obesity surgery were within the reference values reported in controls and seasonal variations were present in several analytes. After surgery, and regardless of the type of intervention, all serum carotenoids dropped following first-order kinetics. Cis/trans ratio of lycopene and ß-carotene did not change after surgery, over the time or between surgical procedures. On a long-term, serum carotenoids were at or below fifth percentile of reference groups. CONCLUSIONS: The chronic low levels of carotenoids in these patients compromise their availability to tissues, constituting an additional risk factor for other clinical conditions. Dietary advice on carotenoid-rich, fortified foods or supplements should be also evaluated in these patients.

Lutein bioavailability from lutein ester-fortified fermented milk: in vivo and in vitro study.

We assessed the bioavailability of lutein from lutein-fortified fermented milk using in vivo and in vitro approaches. Twenty-four volunteers were randomized to take lutein-fortified fermented milk at two levels of fortification. Single-dose bioavailability study (2x100 ml, ca. 8 or 16 mg of lutein) was performed using a three-point approach (baseline, 3.5 and 6.5 h). Multiple-dose study consisted of consuming one serving/day (ca. 4 or 8 mg/100 ml) for 14 days. Blood samples for biochemical, hematological and lutein analysis were drawn at baseline, Day 7 and Day 14. In vitro bioaccessibility was assessed by a static gastrointestinal digestion model. Lutein content, in vitro ester hydrolysis and micellarization, and lutein concentrations achieved in serum were analyzed by HPLC. In vivo, post-prandial response was higher using the high content fermented milk, but the percentage of absorption was not different according to the dose consumed. Net increments at Day 7 and Day 14 were significantly higher on consuming the high-dose milk as well. In vitro, lutein ester hydrolysis was incomplete regardless of the amount initially present. Free lutein released was higher using the high-dose fermented milk, but the percentage of hydrolysis was similar at both levels of fortification. In the micellar phase, the percentage of free and total lutein was not different according to the dose. Our results support the suitability of the fermented milk as a carrier of lutein esters and an in vivo dose-dependent effect upon regular consumption and suggest the usefulness of in vitro models to provide relevant information to predict in vivo responses.