title: Performance of iron spot test with Arabic bread made from fortified white wheat flour.
abstract: BACKGROUND
  The iron spot test (IST) is a simple qualitative technique for determining the presence of added iron in fortified flour. IST performance in bread has never been investigated. If found to perform well, the IST has the potential to provide a field-friendly method for testing bread and thus support the monitoring and evaluation of flour fortification programs.
  
  
  OBJECTIVE
  To assess the performance of the IST in Arabic bread made from white wheat flour.
  
  
  METHODS
  Bread samples were collected from 1,737 households during a national micronutrient survey in Jordan. A subsample of Arabic bread (n = 44) was systematically selected for testing by both the IST and spectrophotometry (criterion reference). Performance measures (sensitivity, specificity, and positive and negative predictive values) were calculated using five cutoffs to define the presence of added iron, including > or = 15.0 ppm (approximate level of natural iron in Arabic bread) and four additional cutoffs based on test performance.
  
  
  RESULTS
  The iron contents of samples testing negative by IST ranged from 10.4 to 18.4 ppm, with one outlier at 41.0 ppm, which was excluded from subsequent analyses. The iron contents of samples testing positive by IST ranged from 16.1 to 38.4 ppm. With the exception of negative predictive values for the two lowest cutoffs (> or = 15.0 and > or = 16.1 ppm), all performance measures exceeded 83.3%.
  
  
  CONCLUSIONS
  These results show promise for the IST as an inexpensive, field-friendly method for testing bread that could have a useful role in the monitoring and evaluation process for flour fortification programs.
authors.affiliation: Epidemic Intelligence Service, Division of Nutrition, Physical Activity, and Obesity, Centers for Disease Control and Prevention, 3311 Toledo Rd., MS P08, Hyattsville, MD 20782, USA. igd1@cdc.gov
authors.forename: Erin
authors.initials: E
authors.lastname: Nichols
authors.forename: Nancy
authors.initials: N
authors.lastname: Aburto
authors.forename: Hanan
authors.initials: H
authors.lastname: Masa'd
authors.forename: James
authors.initials: J
authors.lastname: Wirth
authors.forename: Kevin
authors.initials: K
authors.lastname: Sullivan
authors.forename: Mary
authors.initials: M
authors.lastname: Serdula
mesh_terms: D001939:Bread / Q000032:analysis*; D005433:Flour / Q000032:analysis*; D005504:Food Analysis / Q000379:methods*; D005527:Food, Fortified / Q000032:analysis*; D007501:Iron / Q000032:analysis*; D007597:Jordan; D011786:Quality Control; D014908:Triticum
chemical_list: D007501:Iron