THESIS

would be only 2. In comparison, the glycemic load for a slice of bread is 10; an apple
is 7, and a cup of white rice 26 (Miller et al. 2003).
High fructose corn syrup (HFCS) is manufactured by enzymatically
hydrolyzing a high-glucose corn syrup, isomerizing glucose into fructose (Bray et al.
2004). A typical HFCS contains 42% fructose. Higher fructose corn syrups (55, 90,
and 100%) can be obtained by enrichment of the isomerized syrups (Appl, 1991).
High-fructose corn syrup provides many benefits in reduced-calorie and reduced-fat
systems. High-fructose corn syrup improves texture, helps retain moisture, lowers
water activity, and enhances flavor, color and sweetness. Texturally, fructose has a
low tendency to crystallize, reducing the potential for graining (Nonaka, 1997). In
addition, fructose does not invert in acidic conditions like sucrose does which
eliminates the possibility of changes in texture during storage. Also, fructose’s high
hygroscopicity increases the perception of tenderness in baked goods. In baking
systems, a desirable aroma, color, and flavor develop when the reducing property of
HFCS reacts with proteins (Maillard Reaction). The intense sweetness of HFCS,
especially of HFCS-90, allows use of 10-20% less sweetener per pound in most soft
baked goods. Finally, HFCS is effective at lowering water activity because it is a
monosaccharide creating a high osmotic pressure (Hanover and White. 1993).
6.3.7 The role of other factors for low GI food
Fiber type and amount may also affect the blood glucose raising
potential of foods. Indeed, the effect of added soluble viscous dietary fibers on the
reduction of both glycaemic and insulinaemic responses has been largely reported.
Some effects of insoluble fibers and dietary resistant starch on short-term postprandial
glycaemia have been also reported, but the effect is weaker. The lowering
effect of resistant starch on blood glucose (by replacing rapidly the digestible starch
fraction) has also been underline. However, most of these effects vary greatly
depending on the physicochemical properties of fibers and may be affected by the
physicochemical parameter of food processes. Co-ingestion of fat with carbohydrates
(as part of the food, or added) can lower the post-prandial glycemic response to foods.
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