title: Storage at -80°C preserves the antioxidant capacity of preterm human milk.
abstract: OBJECTIVE
  It is essential to establish optimum parameters for maintaining the quality of stored milk until the moment of consumption with minimal deterioration of its properties. The aim of the study was to evaluate total antioxidant capacity (TAC) and total oxidation status (TOS) of fresh and freeze-stored samples (at -80°C) of preterm human milk (HM).
  
  
  METHODS
  Samples of colostrum were collected from 98 healthy women within the first 4 days after delivery. The total milk volume collected (6 ml) was divided in two aliquot parts: 3 ml for the fresh analysis which was done immediately after the extraction and 3 ml for storage under freezing conditions at -80°C for three months. The antioxidant status and oxidative stress of the fresh and stored breast milk were assessed via determination of TAC and TOS levels.
  
  
  RESULTS
  The mean gestational age and the birth weight of the infants were 31.26 ± 2.93 weeks and 1620 ± 581.91 g; respectively. There were no significant correlations between maternal age, route of delivery and milk oxidative stress. There was no significant difference between the levels of TAC, TOS and the oxidative stress index in fresh and freeze-stored samples of colostrum in preterm HM (p > 0.05).
  
  
  CONCLUSIONS
  Freeze storage of preterm HM at -80°C for three months preserves the antioxidant capacity without changing oxidative status of HM, which could be noteworthy for the preterm infant nutrition.
authors.affiliation: Department of Neonatology, Zekai Tahir Burak Maternity Teaching Hospital, Ankara, Turkey.
authors.forename: Arzu
authors.initials: A
authors.lastname: Akdag
authors.forename: Fatma Nur
authors.initials: FN
authors.lastname: Sari
authors.forename: Evrim Alyamac
authors.initials: EA
authors.lastname: Dizdar
authors.forename: Nurdan
authors.initials: N
authors.lastname: Uras
authors.forename: Semra
authors.initials: S
authors.lastname: Isikoglu
authors.forename: Ozcan
authors.initials: O
authors.lastname: Erel
authors.forename: Ugur
authors.initials: U
authors.lastname: Dilmen
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000032:analysis*; D015925:Cryopreservation; D005260:Female; D005615:Freezing; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D039382:Maternal Nutritional Physiological Phenomena; D008895:Milk, Human / Q000737:chemistry*; D018384:Oxidative Stress / Q000502:physiology; D047928:Premature Birth; D011309:Preservation, Biological; D011446:Prospective Studies; D012189:Retrospective Studies; D013048:Specimen Handling; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: D000975:Antioxidants
keywords: freeze stored; human milk; preterm infant; total antioxidant capacity