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 nonesterified (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.