Determination of free apocarotenoids and apocarotenoid esters in human colostrum

The presence of carotenoids in human colostrum has been reported in the literature, and xanthophyll esters in human colostrum were recently detected for the first time. However, no published studies have reported whether apocarotenoids, which are metabolites derived from carotenoid enzymatic or nonenzymatic oxidative cleavage, are present in human colostrum. Therefore, the purpose of the present study was to search for the possible occurrence of apocarotenoids, including apocarotenoid esters, in human colostrum for the first time by applying an online supercritical fluid extraction-supercritical fluid chromatography-tandem mass spectrometry methodology. Recent evidence related to apocarotenoid transcriptional activity has suggested that they may have beneficial health properties superior to those of their parent carotenoids. Three different apocarotenoids, namely apo-8'-β-carotenal, apo-8'-lycopenal, and β-citraurin, were identified in intact human colostrum samples, with average concentrations of 85 nmol L^-1, 54.6 nmol L^-1, and 75.4 nmol L^-1, respectively. The overall detection of 16 different free apocarotenoids and 10 different apocarotenoid fatty acid esters in human colostrum was achieved here for the first time. Their occurrence in human colostrum certainly has implications for newborn health status, since colostrum is the only form of food for the newborn during the very first days of life. Graphical abstract.