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texture of foods and affect the breakdown of the amylose chain resulting in
alteration of postprandial glycemic and insulin response ( Bjorck, Granfeldt,
Liljeberg, Tovar, & Asp, 1994 ). Studies using various foods such as legumes,
cereals, and fruits have demonstrated this effect of processing on carbohy-
drate availability, digestibility, and in vivo glycemic response ( Bjorck
et al., 1994 ) . In cereal grains, the refining process removes the indigestible
fiber, leaving a pure starchy carbohydrate thus affecting the carbohydrate
quality and increasing the glycemic impact of the grain. When whole grain
flour is processed to white flour, its energy density increases by 10% due to
loss of most of the dietary fiber present ( Durtschi, 2001 ). This indicates that
the glycemic impact of a food is lowered by increasing the dietary fiber con-
tent of a food ( Riccardi et al., 2008 ) . Other factors related to dietary fiber
that lower the glycemic impact of foods are the viscosity, resistant starch
content, and the compactness of food structures as demonstrated in potato
dumplings ( Riccardi et al., 2008 ) . These studies suggest the need of future
research in food technology to develop low-GI foods.
A study using simple starchy foods such as bread, pasta, and potatoes in
type 2 diabetes patients has shown that isoglucidic portions of these foods can
elicit different glycemic responses with bread showing 68% increase and
potatoes showing 48% increase in blood glucose than spaghetti ( Parillo,
Giacco, Riccardi, Pacioni, & Rivellese, 1985 ). Glycemic response is also
affected by the different cooking procedures such as frying, boiling, baking,
etc. ( Giacco et al., 2001 ) due to alteration of some of the compounds such as
starch, due to change in the content of dietary fiber, resistant starch, or due to
changes in the physical food structure. Including unavailable carbohydrate in
our foods either by simple addition or by replacing glycemic carbohydrates
may be a viable strategy to manage their GI and GL. Many mechanisms are
responsible for this effect. The inclusion of unavailable or lente carbohydrate
interferes with starch digestion and absorption due to their viscous nature by
either inhibiting amylase enzyme or increasing insulin sensitivity ( Jenkins
et al., 2000 ) .
5. DIETARY FIBER AND BLOOD GLUCOSE
Fiber is a well-researched ingredient that can modulate blood glucose.
However, the effects depend upon various physicochemical properties of
fiber such as solubility, molecular weight, etc. There have been contradic-
tory reports on the dose of fiber required to result in a beneficial effect of
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