Impact of extraneous proteins on the gastrointestinal fate of sunflower seed (Helianthus annuus) oil bodies: A simulated gastrointestinal tract study

TY - JOUR

T1 - Impact of extraneous proteins on the gastrointestinal fate of sunflower seed (Helianthus annuus) oil bodies

T2 - A simulated gastrointestinal tract study

AU - Makkhun, Sakunkhun

AU - Khosla, Amit

AU - Foster, Tim

AU - McClements, David Julian

AU - Grundy, Myriam M L

AU - Gray, David A.

PY - 2015/1/1

Y1 - 2015/1/1

N2 - In this study, we examined the physicochemical nature of sunflower seed oil bodies (in the absence and presence of added protein) exposed to gastrointestinal conditions in vitro: crude oil bodies (COB); washed oil bodies (WOB); whey protein isolate-enriched oil bodies (WOB-WPI); and, sodium caseinate enriched-oil bodies (WOB-SC). All oil body emulsions were passed through an in vitro digestion model that mimicked the stomach and duodenal environments, and their physicochemical properties were measured before, during, and after digestion. Oil bodies had a positive charge under gastric conditions because the pH was below the isoelectric point of the adsorbed protein layer, but they had a negative charge under duodenal conditions which was attributed to changes in interfacial composition resulting from adsorption of bile salts. Oil bodies were highly susceptible to flocculation and coalescence in both gastric and duodenal conditions. SDS-PAGE analysis indicated degradation of oleosin proteins (ca. 18-21 kDa) to a greater or lesser extent (dependent on the emulsion) during the gastric phase in all emulsions tested; there is evidence that some oleosin remained intact in the crude oil body preparation during this phase of the digestion process. Measurements of protein displacement from the surface of COBs during direct exposure to bile salts, without inclusion of a gastric phase, indicated the removal of intact oleosin from native oil bodies. This journal is

AB - In this study, we examined the physicochemical nature of sunflower seed oil bodies (in the absence and presence of added protein) exposed to gastrointestinal conditions in vitro: crude oil bodies (COB); washed oil bodies (WOB); whey protein isolate-enriched oil bodies (WOB-WPI); and, sodium caseinate enriched-oil bodies (WOB-SC). All oil body emulsions were passed through an in vitro digestion model that mimicked the stomach and duodenal environments, and their physicochemical properties were measured before, during, and after digestion. Oil bodies had a positive charge under gastric conditions because the pH was below the isoelectric point of the adsorbed protein layer, but they had a negative charge under duodenal conditions which was attributed to changes in interfacial composition resulting from adsorption of bile salts. Oil bodies were highly susceptible to flocculation and coalescence in both gastric and duodenal conditions. SDS-PAGE analysis indicated degradation of oleosin proteins (ca. 18-21 kDa) to a greater or lesser extent (dependent on the emulsion) during the gastric phase in all emulsions tested; there is evidence that some oleosin remained intact in the crude oil body preparation during this phase of the digestion process. Measurements of protein displacement from the surface of COBs during direct exposure to bile salts, without inclusion of a gastric phase, indicated the removal of intact oleosin from native oil bodies. This journal is

UR - http://www.scopus.com/inward/record.url?scp=84928042936&partnerID=8YFLogxK

U2 - 10.1039/c4fo00422a

DO - 10.1039/c4fo00422a

M3 - Article

C2 - 25284307

AN - SCOPUS:84928042936

SN - 2042-6496

VL - 6

SP - 125

EP - 134

JO - Food & Function

JF - Food & Function

IS - 1

ER -