title: Do thawing and warming affect the integrity of human milk?
abstract: OBJECTIVE
  To evaluate the integrity of the human milk (pH, bacterial counts, host defense factors and nutrients) subjected to thawing, warming, refrigeration and maintenance at room temperature.
  
  
  METHODS
  Mothers in the neonatal intensive care unit donated freshly expressed milk. A baseline sample was stored at -80 °C and the remainder of the milk was divided and stored for 7 days at -20 °C. The milk was then subjected to two methods of thawing and warming: tepid water and waterless warmer. Thawed milk also was refrigerated for 24 h prior to warming. Lastly, warmed milk was maintained at room temperature for 4 h to simulate a feeding session. Samples were analyzed for pH, bacterial colony counts, total fat and free fatty acids, and the content of protein, secretory IgA and lactoferrin. Data were analyzed by repeated-measures analysis of variance and paired t test.
  
  
  RESULTS
  There were no differences between processing methods and no changes in fat, protein, lactoferrin and secretory immunoglobulin A with processing steps. Milk pH and bacterial colony counts declined while free fatty acids rose with processing. Refrigeration of thawed milk resulted in greater declines in pH and bacteria and increases in free fatty acids. Bacterial colony counts and free fatty acids increased with maintenance at room temperature.
  
  
  CONCLUSIONS
  The integrity of the milk was affected similarly by the two thawing and warming methods. Thawing and warming change the integrity of previously frozen human milk, but not adversely. Concerns about maintaining warmed milk at room temperature need to be explored.
authors.affiliation: Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York, New Hyde Park, NY, USA.
authors.forename: D
authors.initials: D
authors.lastname: Handa
authors.affiliation: Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York, New Hyde Park, NY, USA.
authors.forename: A F
authors.initials: AF
authors.lastname: Ahrabi
authors.affiliation: 1] Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York, New Hyde Park, NY, USA [2] Lilling Family Neonatal Research Lab, Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: C N
authors.initials: CN
authors.lastname: Codipilly
authors.affiliation: Lilling Family Neonatal Research Lab, Feinstein Institute for Medical Research, Manhasset, NY, USA.
authors.forename: S
authors.initials: S
authors.lastname: Shah
authors.affiliation: Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, USA.
authors.forename: S
authors.initials: S
authors.lastname: Ruff
authors.affiliation: Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York, New Hyde Park, NY, USA.
authors.forename: D
authors.initials: D
authors.lastname: Potak
authors.affiliation: Department of Animal & Veterinary Science, University of Idaho, Moscow, ID, USA.
authors.forename: J E
authors.initials: JE
authors.lastname: Williams
authors.affiliation: Department of Animal & Veterinary Science, University of Idaho, Moscow, ID, USA.
authors.forename: M A
authors.initials: MA
authors.lastname: McGuire
authors.affiliation: 1] Neonatal-Perinatal Medicine, Cohen Children's Medical Center of New York, New Hyde Park, NY, USA [2] Lilling Family Neonatal Research Lab, Feinstein Institute for Medical Research, Manhasset, NY, USA [3] Hofstra North Shore-LIJ School of Medicine, Hempstead, NY, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Schanler
mesh_terms: D015169:Colony Count, Microbial; D004041:Dietary Fats / Q000032:analysis; D005615:Freezing; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007071:Immunoglobulin A, Secretory / Q000032:analysis; D007781:Lactoferrin / Q000032:analysis; D008422:Materials Testing; D008894:Milk Proteins / Q000032:analysis; D008895:Milk, Human / Q000737:chemistry* / Q000382:microbiology; D012034:Refrigeration
chemical_list: D004041:Dietary Fats; D007071:Immunoglobulin A, Secretory; D008894:Milk Proteins; D007781:Lactoferrin