title: Durum wheat particle size affects starch and protein digestion in vitro.
abstract: OBJECTIVE
  The term bioaccessibility refers to the proportion of a nutrient released from a complex food matrix during digestion and, therefore, becoming potentially available for absorption in the gastrointestinal tract. In the present study, we assessed the starch and protein bioaccessibility from a range of wheat endosperm products differing in particle size.
  
  
  METHODS
  Five porridge meals (size A, flour, mean particle size 0.11 mm, size B, small, mean particle size 0.38 mm, size C, semolina, mean particle size 1.01 mm, size D, medium, mean particle size 1.44 mm, size E, large, mean particle size 1.95 mm) with theoretically different postprandial glycaemic responses were subjected to oral processing in vitro, followed by simulated gastric and duodenal digestion.
  
  
  RESULTS
  A significant increase (P < 0.001) in starch degradation was observed in size A (52%) compared with size E (25%). Both sizes C and D gave less, although not significantly, digestible starch (32 and 28%, respectively). The glucose release significantly decreased as the particle size of the meal increased (92.16% detected for size A vs 47.39% for size E). In agreement with starch degradation and glucose release, size A gave the most digestible protein.
  
  
  CONCLUSIONS
  This data provide further evidence that, by decreasing the size of wheat endosperm, starch release and glycaemic response are enhanced. We also showed that protein bioaccessibility followed a similar trend as for starch digestion. Finally, these results support the hypothesis that different degrees of starch encapsulation elicit different blood glucose responses.
authors: The Model Gut, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.|Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy.
authors: Giuseppina
authors: G
authors: Mandalari
authors: The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.
authors: Zara
authors: Z
authors: Merali
authors: The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.
authors: Peter
authors: P
authors: Ryden
authors: The Model Gut, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.
authors: Simona
authors: S
authors: Chessa
authors: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy.
authors: Carlo
authors: C
authors: Bisignano
authors: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy.
authors: Davide
authors: D
authors: Barreca
authors: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy.
authors: Ersilia
authors: E
authors: Bellocco
authors: Dipartimento di Scienze Chimiche, Biologiche, Farmaceutiche ed Ambientali, University of Messina, Sal. Sperone 31, 98166, Messina, Italy.
authors: Giuseppina
authors: G
authors: Laganà
authors: The Model Gut, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK.
authors: Richard M
authors: RM
authors: Faulks
authors: The Biorefinery Centre, Institute of Food Research, Norwich Research Park, Colney, Norwich, NR4 7UA, UK. keith.waldron@ifr.ac.uk.
authors: Keith W
authors: KW
authors: Waldron
mesh_terms: D000681:Amylases / Q000378:metabolism; D001646:Bile / Q000378:metabolism; D001682:Biological Availability; D001786:Blood Glucose / Q000378:metabolism; D004063:Digestion; D004386:Duodenum / Q000378:metabolism; D002523:Edible Grain / Q000737:chemistry*; D005753:Gastric Mucosa / Q000201:enzymology; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008049:Lipase / Q000378:metabolism; D010179:Pancreas / Q000201:enzymology; D010316:Particle Size; D010434:Pepsin A / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D012463:Saliva / Q000276:immunology; D013213:Starch / Q000378:metabolism* / Q000493:pharmacokinetics; D014908:Triticum
chemical_list: D001786:Blood Glucose; D010940:Plant Proteins; D013213:Starch; D008049:Lipase; D000681:Amylases; D010434:Pepsin A; D005947:Glucose
keywords: Glycaemic response; In vitro models; Starch digestion; Wheat endosperm