Nutrient composition of banked human milk in Brazil and influence of processing on zinc distribution in milk fractions.
OBJECTIVE
We measured the contents of fat, protein, lactose, calcium, phosphorus, zinc, iron, copper, and vitamin A in processed mature milk samples (individual, n = 60, and pooled, n = 10) from a reference human milk bank in Brazil and assessed the effect of pasteurization followed by freezing on the nutrient composition and the pattern of zinc distribution in fractions (fat, whey, and casein) of milk samples (n = 15).


RESULTS
Mean nutrient concentrations were within expected ranges in mature milk from healthy women, except fat, which was lower. Interindividual variability of nutrient concentrations was high (coefficient of variation, 21-62%) but reduced overall in pooled samples. Processing of milk samples did not affect the nutrient contents but did cause a significant shift (P < 0.04) in the relative distribution of zinc, with a decrease in the whey fraction and an increase in the fat fraction.


CONCLUSIONS
Redistribution and possible alterations in the zinc-binding pattern during processing in human milk banks may reduce zinc bioavailability to the infant.
Góes
Heloísa C A
HC
Laboratorio de Bioquimica Nutricional e de Alimentos, Departamento de Bioquimica, Instituto de Quimica, Universidade Federal do Rio de Janeiro, 21949-900 Rio de Janeiro, Brazil.
Torres
Alexandre G
AG
Donangelo
Carmen M
CM
Trugo
Nadia M F
NM
D001682:Biological Availability; D001938:Brazil; D002118:Calcium / Q000032:analysis; D002364:Caseins / Q000032:analysis; D003300:Copper / Q000032:analysis; D005260:Female; D005511:Food Handling; D006801:Humans; D007501:Iron / Q000032:analysis; D007785:Lactose / Q000032:analysis; D008055:Lipids / Q000032:analysis; D017784:Milk Banks; D008894:Milk Proteins / Q000032:analysis; D008895:Milk, Human / Q000737:chemistry*; D009753:Nutritive Value; D010758:Phosphorus / Q000032:analysis; D014801:Vitamin A / Q000032:analysis; D000067816:Whey Proteins; D015032:Zinc / Q000032:analysis* / Q000493:pharmacokinetics
D002364:Caseins; D008055:Lipids; D008894:Milk Proteins; D000067816:Whey Proteins; D014801:Vitamin A; D010758:Phosphorus; D003300:Copper; D007501:Iron; D007785:Lactose; D015032:Zinc; D002118:Calcium