title: NUTRALYS(®) pea protein: characterization of in vitro gastric digestion and in vivo gastrointestinal peptide responses relevant to satiety.
abstract: BACKGROUND
  Pea protein (from Pisum sativum) is under consideration as a sustainable, satiety-inducing food ingredient.
  
  
  OBJECTIVE
  In the current study, pea-protein-induced physiological signals relevant to satiety were characterized in vitro via gastric digestion kinetics and in vivo by monitoring post-meal gastrointestinal hormonal responses in rats.
  
  
  METHODS
  Under in vitro simulated gastric conditions, the digestion of NUTRALYS(®) pea protein was compared to that of two dairy proteins, slow-digestible casein and fast-digestible whey. In vivo, blood glucose and gastrointestinal hormonal (insulin, ghrelin, cholecystokinin [CCK], glucagon-like peptide 1 [GLP-1], and peptide YY [PYY]) responses were monitored in nine male Wistar rats following isocaloric (11 kcal) meals containing 35 energy% of either NUTRALYS(®) pea protein, whey protein, or carbohydrate (non-protein).
  
  
  RESULTS
  In vitro, pea protein transiently aggregated into particles, whereas casein formed a more enduring protein network and whey protein remained dissolved. Pea-protein particle size ranged from 50 to 500 µm, well below the 2 mm threshold for gastric retention in humans. In vivo, pea-protein and whey-protein meals induced comparable responses for CCK, GLP-1, and PYY, that is, the anorexigenic hormones. Pea protein induced weaker initial, but equal 3-h integrated ghrelin and insulin responses than whey protein, possibly due to the slower gastric breakdown of pea protein observed in vitro. Two hours after meals, CCK levels were more elevated in the case of protein meals compared to that of non-protein meals.
  
  
  CONCLUSIONS
  These results indicate that 1) pea protein transiently aggregates in the stomach and has an intermediately fast intestinal bioavailability in between that of whey and casein; 2) pea-protein- and dairy-protein-containing meals were comparably efficacious in triggering gastrointestinal satiety signals.
authors.affiliation: Department of Health, NIZO Food Research, Ede, The Netherlands; info@nizo.com.
authors.forename: Joost
authors.initials: J
authors.lastname: Overduin
authors.affiliation: Department of Biology and Nutrition, Roquette Frères, Lestrem, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Guérin-Deremaux
authors.affiliation: Nutrition Management, Roquette Frères, Lestrem, France.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wils
authors.affiliation: Department of Health, NIZO Food Research, Ede, The Netherlands.
authors.forename: Tim T
authors.initials: TT
authors.lastname: Lambers
keywords: dairy proteins; gastrointestinal peptides; in vitro gastric digestion; pea protein; satiety