Attenuation of glycemic responses by oat β-glucan solutions and viscoelastic gels is dependent on molecular weight distribution

• Published in: Food & function Vol. 4; no. 3; pp. 41 - 48
• Main Authors: Kwong, Melissa G. Y, Wolever, Thomas M. S, Brummer, Yolanda, Tosh, Susan M
• Format: Journal Article
• Language: English
• Published: England 26.02.2013
• Subjects: Adolescent; Adult; Aged; Avena - chemistry; beta -Glucan; beta-glucans; beta-Glucans - chemistry; beta-Glucans - pharmacology; Beverages; Blood; blood glucose; Blood Glucose - drug effects; Chemical Phenomena; Female; Food; Gels; Gels - chemistry; Glucose; glycemic effect; Glycemic Index - drug effects; Humans; liquids; Male; Middle Aged; Molecular Weight; oats; Postprandial Period - drug effects; Regression Analysis; solubilization; viscoelasticity; Viscosity; Young Adult
• ISSN: 2042-6496; 2042-650X; 2042-650X
• DOI: 10.1039/c2fo30202k

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. Oat β-glucan viscous solutions, but not gels, attenuate postprandial glycemic responses.