Research Activities 2015

Assist. Prof. Eric Chan Wei Chiang

Main research areas

1. Effects of heat treatment on bioactivity of food

2. Isolation of bioactive natural products

3. Production of carboxymethyl hydrogels

Effects of heat treatment

Thermal treatments used in food preparation and processing is widely considered to degrade biomolecules and reduce any bioactive properties

However, our recent showed thermal and non-thermal drying treatments enhanced the bioactivity of certain herbs

The herbs studied were Etlingera elatior (Torch ginger), Morus alba (Mulberry) and Thunbergia laurifolia (Blue trumpet vine).

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

Microwave-drying enhanced the AOP of T. laurifolia leaves with 34% increase in total phenolic content and 67% increase in radical scavenging ability

Leaves of M. alba responded positively to Microwave-drying, Oven-drying and Freeze-drying.

Freeze-drying enhanced the AOP of leaves of E. elatior

Effects of heat treatment

Overlay of chromatograms showed greater amounts of minor compounds in freeze-dried than fresh leaves.

The HPLC chromatogram of freeze-dried leaves of E. elatior showed greater amounts of minor compounds than fresh leaves

Undergraduate students

Suit Ying

Phui Yan

Michelle

Quorum quenching by methyl gallate isolated from cashew leaves Methanolic extract of cashew leaves was assessed

for quorum sensing (QS) inhibition using the disc-diffusion assay with Chromobacterium violaceum

The extract exhibited strong anti-QS activity

From the extract, methyl gallate was isolated by column chromatography and identified by NMR and MS spectroscopy, and quantified using reversed-phase HPLC.

HPLC quantfication

Content of methyl gallate was found to be 1830 ± 180 μg/g of leaves

Postgraduate alumni

Yuen Ping produced 9 publications upon completion of her MSc.

Further research with UM-HIR

Thiba a PhD candidate under Dr Chan Kok Gan would be testing herbs for quorum quenching on different E. coli strains which produce long-chain and short-chain AHL signalling molecules. 

FRGS:Root Targeted Delivery Vehicle for fertilizers using cellulose fromagricultural waste Malaysian agriculture is very

productive and generates large amounts of wastes annually

Plant biomass from agricultural waste is a rich underutilised source of cellulose that can be used to manufacture carboxymethyl cellulose

Waste from Malaysian agriculture can be fully utilised to create a root targeted, slow-release fertilizer system

Root targeted delivery systems

Hydrogel beads Commercial RTDV Estate wastewater

Current MSc students

Pei Xin and Caroline

Thank you