title: In vitro assessment of the bioaccessibility of tocopherol and fatty acids from sunflower seed oil bodies.
abstract: The in vitro digestibility (proteolytic and lipolytic) and bioaccessibility of nutritionally important compounds (alpha-tocopherol and fatty acids) have been studied for natural sunflower ( Helianthus annuus ) oil body suspensions in comparison to artificial emulsions emulsified with polyoxyethylene-20-sorbitan-monolaurate (Tween 20) or whey protein isolate. Proteolytic digestion of emulsions with pepsin (pH 2) promoted significant increases in mean particle size of the whey protein isolate stabilized emulsion (1.8-2.9 mum) and oil bodies (2.3-22.5 mum) but not the Tween 20 stabilized emulsions. SDS-PAGE of proteolytic digestion products suggested degradation of the stabilizing oleosin protein (ca. 18-21 kDa) in oil bodies. The rate of oil body hydrolysis with lipase was significantly slower than the lipase-catalyzed hydrolysis of the artificial emulsions and exhibited a prolonged lag phase. Results from simulated human digestion in vitro suggested that the mean bioaccessibility of alpha-tocopherol and total fatty acids from oil bodies (0.6 and 8.4%, respectively) was significantly lower than that from the Tween 20 stabilized emulsion (35 and 52%, respectively) and the whey protein isolate stabilized emulsion (17 and 33%, respectively). These in vitro results suggest that oil bodies could provide a natural emulsion in food that is digested at a relatively slow rate, the physiological consequence of which may be increased satiety.
authors.affiliation: Plymouth Marine Laboratory, Prospect Place, The Hoe, Plymouth, England.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: White
authors.forename: Ian D
authors.initials: ID
authors.lastname: Fisk
authors.forename: Sakunkhun
authors.initials: S
authors.lastname: Makkhun
authors.forename: David A
authors.initials: DA
authors.lastname: Gray
mesh_terms: D001682:Biological Availability; D004063:Digestion; D004655:Emulsions / Q000737:chemistry* / Q000378:metabolism; D005227:Fatty Acids / Q000378:metabolism*; D006801:Humans; D008049:Lipase / Q000378:metabolism; D008894:Milk Proteins / Q000737:chemistry; D010316:Particle Size; D010434:Pepsin A / Q000378:metabolism; D010938:Plant Oils / Q000737:chemistry*; D011136:Polysorbates; D000074242:Sunflower Oil; D000067816:Whey Proteins; D024502:alpha-Tocopherol / Q000378:metabolism*
chemical_list: D004655:Emulsions; D005227:Fatty Acids; D008894:Milk Proteins; D010938:Plant Oils; D011136:Polysorbates; D000074242:Sunflower Oil; D000067816:Whey Proteins; D008049:Lipase; D010434:Pepsin A; D024502:alpha-Tocopherol