Dietary flavour compounds transfer to human milk differentially

H. Hausner (1), W.L.P. Bredie (1), C. Mølgaard (2), M.A. Petersen (1), P. Møller (1)
(1) Department of Food Science
(2) Department of Human Nutrition
The Faculty of Life Sciences, University of Copenhagen, Denmark
 hlhlife.ku.dk

Transfer of dietary flavour compounds into human milk, along with odours present in amniotic fluid, are believed to constitute the infant’s early flavour experiences. This study addresses the dynamics of transfer of flavours from the mother’s diet to her breast milk using a within and between-subject design, controlled for time after intake.

Eighteen lactating mothers completed three test days on which they expressed a baseline milk sample before lunch and prior to ingestion of capsules containing 100 mg d-carvone, l-menthol, 3-methylbutyl acetate and trans-anethole, respectively. Milk samples were collected at 0, 2, 4, 6 and 8 h post ingestion and analyzed by a dynamic headspace method and GC-MS. The quantities were adjusted for variations in fat content (Creamatocrit method).

The concentration-time profiles revealed milk concentration peaks 2 h post-ingestion for d-carvone and trans-anethole, though trans-anethole peaked at 4 h in five subjects and d-carvone peaked at 6 h in six subjects. The concentration profile of l-menthol showed a plateau pattern without significant time peaks. All flavour compounds approached baseline levels 8 h post-ingestion. The ‘fruity’ ester 3-methylbutyl acetate could not be detected in any of the milk samples. Mean milk peak concentrations were 2.32 mcg/mL (mcg = microgramm) for trans-anethole, 1.05 mcg/mL for d-carvone and 0.80 mcg/mL for l-menthol. Less than one percent of the maternal dose was transmitted to the infant on a daily basis. Flavours appear to be transmitted differentially from the mother’s diet to her breast milk. Certain volatiles may be degraded or resist absorption in the gastro-intestinal tract, whereas others may enter the blood circulation at different rates, e.g. as conjugates and are gradually removed again. The study supports that human milk provides potential for varying chemosensory experiences to the infant; however, volatiles from the diet are transferred selectively and in relatively low amounts.