Enhancement of antioxidant properties by drying treatments
-
Upload
eric-wei-chiang-chan -
Category
Food
-
view
1.595 -
download
1
description
Transcript of Enhancement of antioxidant properties by drying treatments
![Page 1: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/1.jpg)
ANTIOXIDANT PROPERTIES OF THREE
SELECTED HERBS AND THE
ENHANCEMENT
EFFECTS OF DRYING TREATMENTS
Assist. Prof. Eric Chan Wei Chiang
![Page 2: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/2.jpg)
Overview
Thermal treatments used in food preparation and
processing is widely considered to degrade
biomolecules and reduce any bioactive properties
However, our recent work on the antioxidant
properties (AOP) of leaves of selected herbs
showed that three displayed enhancement
effects of thermal and non-thermal drying
treatments.
The herbs studied were Etlingera elatior (Torch
ginger), Morus alba (Mulberry) and Thunbergia
laurifolia (Blue trumpet vine).
![Page 3: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/3.jpg)
Antioxidant assays and drying
treatments
Assessment of Antioxidant
Properties
Total phenolic content (TPC)
DPPH Radical Scavenging
(AEAC)
Ferric reducing power (FRP)
Drying treatments
Microwave drying
Oven drying
Sun-drying
Air drying
Freeze drying
![Page 4: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/4.jpg)
Microwave-drying enhanced
the AOP of T. laurifolia leaves
with 34% increase in TPC
and 67% increase in AEAC
as confirmed by the half-leaf
test.
A likely cause for the
increase in antioxidant
activity following microwave-
drying was was the release
of bound phenolic
compounds, brought about
by the breakdown of cellular
constituents
Another possible explanation
is the rapid inactivation of
polyphenol oxidase (PPO)
activity in samples due to
microwave irradiation
Thunbergia laurifolia
![Page 5: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/5.jpg)
Morus alba
Leaves of M. alba responded positively to Microwave-drying, Oven-
drying and Freeze-drying.
The increase in antioxidant properties is likely due to the release of
bound phenolic compounds.
Furthermore, the oxidative enzymes in M. alba was not activated by
oven drying as observed in T. laurifolia.
![Page 6: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/6.jpg)
Freeze-drying enhanced the
AOP of leaves of E. elatior
The antioxidants within the
leaves were not heat stable
The HPLC chromatogram of
freeze-dried leaves of E.
elatior showed greater
amounts of minor compounds
than fresh leaves
Etligera elatior
![Page 7: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/7.jpg)
Overlay of chromatograms
showed greater amounts of
minor compounds in freeze-
dried than fresh leaves.
![Page 8: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/8.jpg)
Other research capabilities
Bioassay guided isolation of
phytochemicals for
NMR and MS
Synthesis of carboxymethyl cellulose
Encapsulation of nutraceuticals
![Page 9: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/9.jpg)
Other research capabilities
![Page 10: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/10.jpg)
The MSc. student behind it all
![Page 11: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/11.jpg)
Yuen Ping’s research
team
Lainey Audrey Hui Qi
Alice Pang Kwok Meng
![Page 12: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/12.jpg)
Monash Science Symposium
![Page 13: Enhancement of antioxidant properties by drying treatments](https://reader033.fdocuments.in/reader033/viewer/2022052909/55977a971a28ab85468b4644/html5/thumbnails/13.jpg)
Thank youCheck out my blog here:
http://www.scoop.it/u/eric-chan-wei-chiang