title: Attenuation of glycemic responses by oat β-glucan solutions and viscoelastic gels is dependent on molecular weight distribution.
abstract: Oat β-glucan attenuates postprandial glycemic responses when solubilized to form viscous solutions. High molecular weight (MW) β-glucan is associated with high solution viscosity, which is in turn associated with lower glycemic responses. However, low MW β-glucan is also able to form viscoelastic gels. The effect of low (145,000 g mol(-1)) and high (580,000 g mol(-1)) MW β-glucan presented as liquid drinks and gels on glycemic responses was determined. Healthy subjects (n = 15) consumed 50 g glucose drinks with no β-glucan; 4 g low MW; or 4 g high MW β-glucan; and gels containing 4 g low MW; 2 g low plus 2 g high MW; or 3 g high plus 1 g low MW β-glucan. Overall, β-glucan solutions elicited lower glycemic responses than gels. For gels, peak blood glucose rise (PBGR) decreased with increasing dose of high MW β-glucan (r(2) = 0.976, P > 0.05), and PBGR for the gel with 3 g high-MW was lower than for the control (P < 0.05). However, β-glucan gels retained glucose better than solutions under in vitro analysis. Observed effects were found to be related to the rheological properties of the foods. β-Glucan solutions and not gels effectively attenuated in vivo glycemic responses.
authors.affiliation: Department of Nutritional Sciences, University of Toronto, Toronto, ON, Canada.
authors.forename: Melissa G Y
authors.initials: MG
authors.lastname: Kwong
authors.forename: Thomas M S
authors.initials: TM
authors.lastname: Wolever
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Brummer
authors.forename: Susan M
authors.initials: SM
authors.lastname: Tosh
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018554:Avena / Q000737:chemistry*; D001786:Blood Glucose / Q000187:drug effects*; D055598:Chemical Phenomena; D005260:Female; D005782:Gels / Q000737:chemistry*; D038321:Glycemic Index / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D019518:Postprandial Period / Q000187:drug effects; D012044:Regression Analysis; D014783:Viscosity; D055815:Young Adult; D047071:beta-Glucans / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D001786:Blood Glucose; D005782:Gels; D047071:beta-Glucans