title: Effect of food matrix microstructure on stomach emptying rate and apparent ileal fatty acid digestibility of almond lipids.
abstract: Almond lipids can be consumed in different forms such as nuts, oil-in-water emulsions or oil. The stomach emptying rate (SER) of almond lipids (0.2 g of fat per 2 mL of almond lipid suspension) as a function of the food matrix was studied using magnetic resonance spectroscopy based on the stomach emptying of a marker (AlCl3-6H2O) in the growing rat. Chyme and digesta samples were collected following serial gavaging (0.2 g of fat per 2 mL of almond lipid suspension) to study microstructural changes and determine the apparent ileal digestibility of almond fatty acids as a function of the native food matrix. The T(1/2) for the stomach emptying of crushed whole almonds and almond cream (194 ± 17 min and 185 ± 19 min, respectively) were not different (P > 0.05) from that of a gastric-stable Tween-oil emulsion (197 ± 19 min). The T(1/2) values for a sodium caseinate (NaCas)-oil emulsion (145 ± 11 min) and a gastric-unstable Span-oil emulsion (135 ± 7 min) were different (P < 0.05) from those for crushed whole almonds, almond cream and Tween-oil emulsion, while almond milk and oil emptied at an intermediate rate (157 ± 9 min and 172 ± 11 min, respectively). Extensively coalesced emulsions under gastric conditions (almond oil, almond cream and Span-oil) had lower (P < 0.05) overall apparent ileal fatty acid digestibility (85.8%, 75.8% and 74.3%, respectively) than crushed whole almonds, almond milk, NaCas-oil and Tween-oil emulsions (91.0%, 92.2%, 92.1% and 88.7%, respectively). The original food matrix and structural changes occurring within the gastrointestinal tract had an impact on SER and ileal fatty acid digestibility of the almond preparations.
authors: Riddet Institute, Massey University, Private Bag 11 222, Palmerston North 4442, New Zealand. Sophie.Gallier@danone.com sophie.gallier@otago.ac.nz.
authors: Sophie
authors: S
authors: Gallier
authors: Shane M
authors: SM
authors: Rutherfurd
authors: Paul J
authors: PJ
authors: Moughan
authors: Harjinder
authors: H
authors: Singh
mesh_terms: D000818:Animals; D004041:Dietary Fats / Q000378:metabolism; D004063:Digestion; D004655:Emulsions; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D005746:Gastric Emptying / Q000502:physiology*; D005766:Gastrointestinal Contents / Q000737:chemistry; D007082:Ileum / Q000378:metabolism*; D050356:Lipid Metabolism / Q000502:physiology; D009682:Magnetic Resonance Spectroscopy; D009754:Nuts / Q000737:chemistry; D010938:Plant Oils / Q000737:chemistry; D019518:Postprandial Period; D027861:Prunus / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004041:Dietary Fats; D004655:Emulsions; D005227:Fatty Acids; D010938:Plant Oils; C068582:almond oil