HI is considered as the presumptive measure of the glycemic index (GI) in healthy subjects. It was reported that
the postprandial responses to starchy foods and beverages may be modified by a number of factors, including processing conditions. The disruption of the structure present in the native starch by gelatinization usually increases the susceptibility to enzyme degradation in vitro, and the availability for digestion and absorption at the level of the small intestine. Thermal processing is the most common method for manufacturing cereals, thus the complete gelatinization of starch is expected.
Usually, flaking results in an incomplete gelatinization, even though the rate of amylolysis could increase. Compared to
wheat flour bread, which was used as the reference, and to the nonfermented beverage, the fermentation with L. plantarum LP09 alone had a noticeable lower value of HI. The addition of hydrolytic enzymes
determined a slight increase of the HI, probably due to the higher release of mono- and di-saccharides. Overall, low HI is determined either by high concentration of fibers or biological acidification,which is more effective than chemical acidification.