Biology Reference
In-Depth Information
An additional ingredient that modulated glycemic response in these products
was fructose used as a sweetener in these functional food products.
The properties of
b
-glucan that resulted in reduced glycemic response
include molecular weight, solubility, and viscosity. Oat bran muffins
prepared with different concentration of
b
-glucan were tested in healthy
subjects by
Tosh, Brummer, Wolever, and Wood (2008)
. They noticed a
dose-dependent effect of
b
-glucan with the 8 g samples showing a more
positive effect on glycemia than a 4-g sample. There was a significant effect
of molecular weight noticed on the peak blood glucose concentration, thus
illustrating the importance of maintaining the molecular weight of
b
-glucan
in the food samples during processing, cooking, and storage. A recent study
on oat-based extruded cereals with
b
-glucan of varying molecular weight
also showed an inverse relationship between the glucose AUC and the
log
10
molecular weight of
b
-glucan and log
10
viscosity of the cereal extracts
M¨kel¨inen et al. looked at the effect of oat
b
-glucan in the form of a
drink reconstituted from a powder on glycemic and insulin effects in healthy
subjects. Oat bran powder with 2, 4, and 6 g
b
-glucan were also frozen to
study the effect of freezing and thawing on the GI and II of the products.
The 4 g dose was the best in lowering the GI and II of the drinks and the
study showed that rather than the actual
b
-glucan content, the extractable
b
-glucan was better correlated to the glycemic and insulin response
suggesting the possible role of solubility and the effect of freezing on the
the effect of food processing on the molecular weight, solubility, and viscos-
ity of oat
b
-glucan and its effect on glycemic response in healthy subjects
(
Regand, Tosh, Wolever, &Wood, 2009
)
. Different test meals such as crisp
bread, porridge, granola, and pasta with 4 g
b
-glucan were used, among
which porridge and granola were effective in maintaining the
b
-glucan
molecular weight and lowering the postprandial glycemic response. The
pasta and bread products were not as effective probably due to the depoly-
merization of
b
-glucan.
The particle size of a test meal is also important in determining its effect
on blood glucose response.
Behall, Scholfield, and Hallfrisch (2005)
com-
pared oat flakes and flour in overweight women and found no effect of par-
ticle size on glycemic response. Although both the oat products reduced the
glucose AUC by 29-36% and barley products (59-65%), the oat products
did not have an effect on insulin response. The difference in
b
-glucan
