Premium
Oxidation products of polyunsaturated fatty acids in infant formulas compared to human milk – A preliminary study
Author(s) -
Michalski MarieCaroline,
Calzada Catherine,
Makino Asami,
Michaud Sabine,
Guichardant Michel
Publication year - 2008
Publication title -
molecular nutrition and food research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.495
H-Index - 131
eISSN - 1613-4133
pISSN - 1613-4125
DOI - 10.1002/mnfr.200700451
Subject(s) - infant formula , polyunsaturated fatty acid , chemistry , food science , malondialdehyde , lipid oxidation , docosahexaenoic acid , vitamin e , fatty acid , chromatography , antioxidant , biochemistry
Information about lipid oxidation in fresh and stored human milk compared with infant formulas is scarce. We aimed to assess n ‐6 and n ‐3 PUFA oxidation in these milks by measuring the 4‐hydroxynonenal (4‐HNE) and 4‐hydroxyhexenal (4‐HHE) content. Human milk samples ( n = 4), obtained from volunteer mothers, were analyzed fresh and after 1 wk at 4°C or 24 h at 18°C. Vitamin E and malondialdehyde (MDA) were measured by HPLC and fatty acid profile by GC. The 4‐HHE and 4‐HNE contents were measured by GC‐MS. Infant formulas ( n = 10) were tested; their fat droplet size was measured by laser light scattering and observed by confocal laser scanning microscopy. Human milk samples contained 31.0 ± 6.3 g/L of lipids and 1.14 ± 0.26 mg/L of vitamin E. Fat droplets were smaller in infant formulas than reported in human milk. The (4‐HHE/ n ‐3 PUFA) ratio was 0.19 ± 0.01 μg/g in fresh human milk (unchanged after storage) versus 3.6 ± 3.1 μg/g in dissolved powder formulas and 4.3 ± 3.8 μg/g in liquid formula. (4‐HNE/ n ‐6 PUFA) was 0.004 ± 0.000 μg/g in fresh milk (0.03 ± 0.01 μg/g after storage) versus 1.1 ± 1.0 μg/g in dissolved powder formulas and 0.2 ± 0.3 μg/g in liquid formula. Infant formulas also contained more MDA than human milk. n ‐3 PUFA were more prone to oxidation than n ‐6 PUFA. Whether threshold levels of 4‐HHE and 4‐HNE would be of health concern should be elucidated.