title: Near infrared spectroscopy-a potentially useful method for rapid determination of fat and protein content in homogenized diets.
abstract: OBJECTIVE
  To investigate the potential of near-infrared reflectance (NIR) spectroscopy as a rapid and non-destructive method to determine total fat and protein in mixed, homogenized and freeze-dried human diets.
  
  
  METHODS
  29 students collected duplicate portions of their diet for four consecutive days. In addition, a detailed food diary was kept. The duplicate portions were analysed for total protein and fat content both by traditional chemical analysis (Kjeldahl and Folch methods) and through the recently developed NIR spectroscopy method. In addition, traditional computerized estimation of nutrient composition was performed.
  
  
  RESULTS
  Plotting of the NIR-predicted fat content against the chemically analysed fat content gave a correlation coefficient of 0. 99. Plotting of the NIR-predicted protein content against the Kjeldahl-analysed protein gave a correlation coefficient of 0.81.
  
  
  CONCLUSIONS
  NIR-spectroscopy seems to be able to determine fat content in mixed, homogenized diets to a high degree of accuracy. In surveys involving duplicate portion sampling this will save time and money. The prediction accuracy for protein was less convincing, but acceptable depending on the need for accurate individual data.
  
  
  BACKGROUND
  Norwegian Food Research Institute, Institute for Nutrition Research at the University of Oslo and the Research Society of the Norwegian Edible Fat Producers and the food company Mills DA. European Journal of Clinical Nutrition (2000) 54, 20-23
authors.affiliation: Institute for Nutrition Research, Faculty of Medicine, University of Oslo, Blindern, Oslo, Norway.
authors.forename: K
authors.initials: K
authors.lastname: Almendingen
authors.forename: H M
authors.initials: HM
authors.lastname: Meltzer
authors.forename: J I
authors.initials: JI
authors.lastname: Pedersen
authors.forename: B N
authors.initials: BN
authors.lastname: Nilsen
authors.forename: M
authors.initials: M
authors.lastname: Ellekjaer
mesh_terms: D004032:Diet; D015930:Diet Records; D004041:Dietary Fats / Q000032:analysis*; D004044:Dietary Proteins / Q000032:analysis*; D005260:Female; D005504:Food Analysis; D006801:Humans; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins