Plasma response to a single dose of dietary beta-cryptoxanthin esters from papaya (Carica papaya L.) or non-esterified beta-cryptoxanthin in adult human subjects: a comparative study.

Many orange-coloured fruits contain beta-cryptoxanthin in its non-esterified as well as its esterified form. Information concerning the absorption of beta-cryptoxanthin, especially with regard to the metabolism of its fatty acid esters, is rather scarce. The present study assessed the plasma concentration reached after consumption of a single dose of native beta-cryptoxanthin esters from papaya (Carica papaya L.) or non-esterified beta-cryptoxanthin in equal total amounts. In a randomized, single-blind crossover study, twelve subjects were served a portion of yoghurt containing esterified or non-esterified beta-cryptoxanthin (1.3 mg absolute) together with a balanced breakfast. Between the two intervention days, there was a 2-week depletion period. After a fasting blood sample had been taken, futher samples were taken from the subjects at 3, 6, 9, 12 and 24 h. The concentration of non-esterified beta-cryptoxanthin in the whole plasma was determined by HPLC; beta-cryptoxanthin identification was confirmed by liquid chromatography-atmospheric pressure chemical ionization-MS analyses. Irrespective of the consumed diet, the plasma beta-cryptoxanthin concentrations increased significantly (P=0.05) and peaked after 6-12 h. The concentration curves, as well as the areas under the curves, were not distinguishable according to two-sided F and t tests (P=0.05). Standardization of beta-cryptoxanthin concentrations to plasma triacylglycerol and cholesterol had no impact on the results. Thus, the present study indicates comparable bioavailability of both non-esterified beta-cryptoxanthin and mixtures of beta-cryptoxanthin esters. The results support the existence of an effective enzymatic cleavage system accepting various beta-cryptoxanthin esters.