MAJOR CAROTENOIDS IN MATURE HUMAN-MILK - LONGITUDINAL AND DIURNAL PATTERNS

The present study was undertaken to quantitate the major carotenoids i n human milk, monitoring their variance among Sore, mid and hind matur e milk samples, during morning, midday, and everting, and among differ ent weeks of lactation. Twenty-three mothers, 6 weeks to 16 weeks post partum, participated in the study. Reversed-phase high performance liq uid chromatography (RP-HPLC) was used to identify and quantitate the m ajor carotenoids Sound in human milk, including lutein/zeaxanthin, bet a cryptoxanthin, lycopene, alpha carotene, and beta carotene. To deter mine the validity of analyzing carotenoids in frozen milk, freshly exp ressed and subsequently frozen milk samples were analyzed Sor Sour mot hers. Freezing did not alter carotenoid concentrations. Wide variation s in carotenoid concentrations existed within and between the mothers. Major carotenoid totals ranged from 29 nM to 493 nM. Complete bi-east expressions at three periods within a day and at specified weekly int ervals allowed the accurate determination of diurnal as well as longit udinal carotenoid concentrations. Diurnal evaluation of carotenoid con centrations suggested a peak at midday and highest longitudinal concen trations were ar IO to 12 weeks. Neither of these trends was statistic ally significant. The analysis of fore, mid, and hind milk carotenoid concentrations demonstrated that hind milk was significantly higher th an fore or mid milk (P < 0.05). (C) Elsevier Science Inc. 1998.