Biology Reference
In-Depth Information
4. LOW GI FOODS CONTAINING STARCH
HYDROLASE INHIBITORS
The ultimate application of the starch hydrolase inhibitor is to be used
as active ingredients in food with low GI for controlling hyperglycemia.
GI describes the level of the postprandial glucose rise in blood as compared
to a reference food (white bread) or glucose (
Jenkins et al., 1981
). Food or
food products can be categorized into high GI (
>
70), low GI (GI
<
55), and
intermediate GI foods based on the GI value (
Brand et al., 1991
). Normally,
starchy staple foods most often has high GI values, which are positively asso-
ciated with the risk of developing type 2 diabetes
(
Barclay & Lie, 2007;
Villegas et al., 2007
)
. Diabetes patients are recommended to take low GI
foods, since it can be digested slowly, and it could improve the long-term
glycemic control (
Brand et al., 1991
). Starch hydrolase inhibitors in edible
plants are ideal choice active ingredients for low GI starchy foods. There are,
however, some hurdles to overcome when applying the botanical extracts in
food matrix and retain their bioactivity when consumed. The active com-
pounds shall be able to survive the processing conditions in terms of their
chemical stability. In addition, although they may interact with biomole-
cules, particularly protein and starch in the food matrix, they shall not lose
the ability to inhibit starch hydrolases when the food enters the gastrointes-
tinal tract (
Bell, 2001
). Finally, the sensory and texture attributes of the foods
shall not be negatively impacted because of the addition of the botanical
extracts. Encapsulation technology is commonly applied to prevent the bio-
active compounds from degrading in the processing conditions and in the
stomach fluid.
4.1. Encapsulation technology for delivering starch
hydrolase inhibitors
The encapsulated bioactive compounds can be protected from the extreme
conditions, therefore enhancing their stability and bioavailability. At the
same time, unpleasant flavor from the plant material can be masked by
encapsulation (
Gibbs, Kermasha, Alli, &Mulligan, 1999
)
. Current encapsu-
lation technology includes spray drying, spray chilling or spray cooling,
extrusion coating, fluidized bed coating, liposome entrapment, coacerva-
tion, inclusion complexation, centrifugal extrusion, and rotational suspen-
sion separation (
Gibbs et al., 1999
)
.
