Biology Reference
In-Depth Information
Encapsulation technology is applied widely in foods containing
a
-glucosidase and
a
-amylase inhibitors as active ingredients and some
examples are discussed here. Black currant extracts showed strong in-
hibitory activity of
a
-glucosidase, but weak inhibitory activity for
a
-amylase and this was suggested to be due to the anthocyanin, which is
Easteal, and Siew (2006)
encapsulated the black currant extract in hot
dispersed (80
C) glucan gel by simple mixing. Large amount of anthocy-
anin could release from gel cubes. Yet, it is unknown whether the encap-
sulated anthocyanins can be applied successfully in low GI food products
Olive leaf extracts could inhibit the activity of human saliva and pancreas
a
-amylase. The active compounds identified include luteolin-7-
O
-ß gluco-
Olive leaf extract could form an inclusion complex with ß-cyclodextrin
upon mixing in aqueous media and subsequently dehydrated by freeze-
Alternatively, olive leaf extract could be encapsulated in chitosan by spray
drying (
Kosaraju, Labbett, Emin, Konczak, & Lundin, 2008
). Grape seeds
could inhibit both of
a
-glucosidase and
a
-amylase because of its high con-
tents of proanthocyanidins (
Liu et al., 2011
). Zhang et al. generated a mix-
ture of maltodextrin (60%) and gum arabic (40%) as a wall material for
encapsulation of grape seed extracts with high efficiency 89% and stability
of procyanidins (
Zhang, Mou, & Du, 2007
). Ellagitannins are dominating
polyphenolic compounds found in cloudberry (
Heinonen, 2007
)
, which
are the main active compounds responsible for
a
-amylase inhibition activity.
Jouppila (2008)
encapsulated phenolic-rich cloudberry extract by freeze
drying, using maltodextrins DE5-8 and DE18.5 as wall materials.
Current progress on encapsulation technology illustrates that encapsula-
tion can stabilize the otherwise thermally or oxidatively sensitive starch
hydrolase inhibitors such as anthocyanins and proanthocyanidins. However,
only time can tell if the encapsulated ingredients are a viable solution in
commercial production of low GI foods. Encapsulation requires additives
such as dextrins and other biopolymers, which add to the cost of food
productions. It would be ideal to avoid using encapsulation method by apply-
ing naturally occurring starch hydrolase inhibitors that are robust against ther-
mal treatment, stable to oxidation, and resistant to acidic conditions in the
