title: Evaluation of human milk titratable acidity before and after addition of a nutritional supplement for preterm newborns.
abstract: OBJECTIVE
  To evaluate the initial Dornic acidity in raw human milk, after pasteurization and after heating and dilution of a dietary supplement for preterm infants.
  
  
  METHODS
  A quantitative, descriptive, and experimental study was carried out with a convenience sample at the human milk bank at a Brazilian public maternity, with specialized care for pregnant women and newborns at risk. The eligibility criteria for the study sample included 93 frozen raw human milk in suitable containers with volumes ≥100mL and initial Dornic acidity ≤8° Dornic (°D). Milk acidity of human milk was measured in four stages: in raw human milk (initial); after pasteurization; after the heating of pasteurized milk and dilution of the supplement; and after thirty minutes of supplementation.
  
  
  RESULTS
  The initial acidity was 3.8°D±1.3 (95% CI: 3.56-4.09) with no significant difference in Dornic acidity in pasteurized milk, which was 3.6°D±1.2 (95% CI: 3.36-3.87). The dilution of the supplement in pasteurized milk that was heated significantly increased mean Dornic acidity to 18.6°D±2.2 (95% CI: 18.18-19.11), which remained high after thirty minutes of supplementation at 17.8°D±2.2 (95% CI: 17.36-18.27), considering p<0.05.
  
  
  CONCLUSIONS
  The study observed no significant differences in Dornic acidity of raw human milk and pasteurized human milk; however, the dilution of a human milk supplementation caused a significant increase in acidity. Further investigations are necessary on the influence of this finding on the quality of supplemented milk and its consequences on the health of preterm infants.
authors.affiliation: Universidade Federal do Rio Grande do Norte (UFRN), Maternidade Escola Januário Cicco (MEJC), Natal, RN, Brazil. Electronic address: cibelle_iaskara@yahoo.com.br.
authors.forename: Cibelle Iáskara do Vale
authors.initials: CI
authors.lastname: Pereira
authors.affiliation: Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN, Brazil; Universidade Federal do Rio Grande do Norte (UFRN), Departamento de Nutrição, Natal, RN, Brazil.
authors.forename: Juliana Fernandes Dos Santos
authors.initials: JF
authors.lastname: Dametto
authors.affiliation: Universidade Federal do Rio Grande do Norte (UFRN), Maternidade Escola Januário Cicco (MEJC), Natal, RN, Brazil.
authors.forename: Janaína Cavalcanti Costa
authors.initials: JC
authors.lastname: Oliveira
mesh_terms: D019587:Dietary Supplements; D005260:Female; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007230:Infant, Low Birth Weight / Q000254:growth & development; D007231:Infant, Newborn; D007234:Infant, Premature / Q000254:growth & development; D008895:Milk, Human / Q000737:chemistry*; D061352:Pasteurization / Q000379:methods; D013997:Time Factors
keywords: Acidez titulável; Dietary supplements; Doenças ósseas metabólicas; Human milk; Leite humano; Metabolic bone diseases; Newborn; Recém-nascido; Suplementos nutricionais; Titratable acidity