title: Modification and application of an in vitro assay to examine inositol phosphate degradation in the digestive tract of poultry.
abstract: BACKGROUND
  An in vitro assay was modified to study the disappearance of inositol hexakisphosphate (InsP6) and the formation of lower inositol phosphate (InsP) isomers in the poultry digestive tract, and three experiments investigated the influence of diets with different ingredients and additives. Using the poultry diet as a matrix, the assay simulated the conditions (e.g. pH, temperature, proteolytic enzymes, water content, and retention time) of the crop, stomach, and small intestine, and extraction and analysis of InsP isomers were immediately conducted.
  
  
  RESULTS
  The assay produced highly reproducible results with coefficients of variation ≤10% for an InsP isomer concentration ≥0.4 µmol g-1DM (n = 3), and it was sensitive to the factors that varied in the three experiments.
  
  
  CONCLUSIONS
  The described assay is a suitable tool that can be used to screen feed enzymes and to investigate the effects of supplements in the absence of endogenous phytases. The ease of handling and high reproducibility of the assay indicated that the assay is a rapid and feasible method that can be used to examine the degradation pathway of phytate in feed under gastrointestinal conditions. © 2017 Society of Chemical Industry.
authors.affiliation: Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany.
authors.forename: Vera
authors.initials: V
authors.lastname: Sommerfeld
authors.affiliation: Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany.
authors.forename: Margit
authors.initials: M
authors.lastname: Schollenberger
authors.affiliation: Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany.
authors.forename: Luca
authors.initials: L
authors.lastname: Hemberle
authors.affiliation: Institut für Nutztierwissenschaften, Universität Hohenheim, Stuttgart, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Rodehutscord
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000818:Animals; D019587:Dietary Supplements / Q000032:analysis; D041981:Gastrointestinal Tract / Q000378:metabolism*; D007295:Inositol Phosphates / Q000737:chemistry / Q000378:metabolism*; D007536:Isomerism; D016226:Phosphorus, Dietary / Q000378:metabolism; D011200:Poultry / Q000378:metabolism*
chemical_list: D007295:Inositol Phosphates; D016226:Phosphorus, Dietary
keywords: in vitro; inositol phosphate disappearance; inositol phosphate isomers; phytase; poultry; screening