Biology Reference
In-Depth Information
content. The results showed slightly higher insulin economy for the human
milk per protein amount in the milk and the effect may be attributed to the
amino acid profile of the proteins.
Proteins from various plant and animal sources were compared in a study
to identify their variations on insulinotropic effect (
Nilsson, Stenberg, Frid,
Holst, & Bj¨ rck, 2004
)
. Reconstituted milk, cheese, whey, cod, and wheat
gluten with equivalent quantities of lactose were used as test meals in com-
parison with white bread as reference. The reconstituted milk and whey
protein meals resulted in reduced glucose response, but the insulin response
was higher than that of the reference meal. The effect was more for the whey
protein meal and probably due to increase in specific amino acids such as
leucine, valine, isoleucine, lysine, and threonine, which were increased after
the whey meal. All the other protein meals were considered poor in increas-
ing insulin response.
Bread is a very common food consumed all over the world especially in
large quantities in the Western countries. White bread is usually considered
as high-GI food because of its effect on rapid increase in blood glucose.
Whole grain bread on the other hand has the ability to reduce the blood
glucose response and hence they are considered as medium- or low-GI
food. Sourdough fermentation is a process used in preparing bread that
could result in low glycemic response due to the formation of organic acids
during the fermentation process.
Scazzina, Rio, Pellegrini, and Brighenti
(2009)
used sourdough fermentation on white and whole meal flour and
used two different leavening techniques using sourdough and
Saccharomyces
cerevisiae
to test the glycemic response to the two types of breads. They
found that sourdough-fermented breads using both whole and white flour
resulted in reduced glycemic response compared to the yeast-leavened
bread probably due to increased resistant starch content resulting from
the starch retrogradation caused by the organic acids formed by sourdough
fermentation.
Sourdough fermentation is also used in the preparation of ready-to-eat
breakfast cereals. When wheat flakes were modified by introducing a sour-
dough prefermentation step by suppressing the steam cooking and reducing
the sucrose content and compared with the standard wheat flakes and also a
white wheat bread, the glycemic response of the modified wheat flakes was
et al., 2009
). However, there was a small improvement in the insulin
response of the modified wheat flakes. This study showed that the food
structure is more important than the effect on starch gelatinization.
