Journal of Food Processing & Technology

Comparative studies on the phytochemical content, in vitro antioxidant and antimicrobial properties of aqueous and ethanolic extracts from four Malaysian herbs

International Conference and Exhibition on Food Processing & Technology

November 22-24, 2012 Hyderabad International Convention Centre, India

Nurain Aziman, Noriham Abdullah, Zainon Mohd Noor, Wan Saidatu`l Syida Wan Kamarudin and Khairusy Syakirah Zulkifli

Accepted Abstracts: J Food Process Technol

Abstract:

Epidemiological studies indicate that consumption of herbs has the ability to inhibit the damaging activities of free radicals in the human body. In this study, aqueous and ethanolic extracts of four edible Malaysian herbs namely: Citrus hystrix, Murraya koenigii, Phaeomeria speciosa and Cymbopogon citratus were screened and assessed for their phytochemical compounds, total phenolic and flavonoid content, antioxidant and antimicrobial properties. The presence of alkaloid, flavonoid, saponin and tannin in the herbs studied were screened. Three antioxidant assays with different mechanisms (FRAP, DPPH and β-carotene bleaching assays) were determined. The antimicrobial properties of extracts against four Gram-positive bacteria, four Gramnegative bacteria and two fungus strains were evaluated using Disc diffusion assay. The total phenolic content (TPC) in the aqueous and ethanolic extracts of herbs studied increased in the order C.citratus < C.hystrix ≤ P.speciosa < M.koenigii, while total flavonoid content (TFC) in both extracts of herbs studied increased in the order C.citratus < C.hystrix ≤ M.koenigii < P.speciosa. The aqueous extracts of M.koenigii showed strong antioxidant properties among samples with respect to their Fe3+ reduction ability, free radical scavenging and free radical inhibition activity (2475.33 mMTE/g EW, 333.39 μg/mL and 66.07%, respectively) compared with their respective ethanol extracts. However, the aqueous extracts of P.speciosa showed most effective antimicrobial properties against all Gram-positive bacteria and three Gram-negative bacteria, followed by ethanolic M.koenigii which showed inhibition against Gram-positive bacteria only. A high and positive correlation was observed between TPC and TFC in both aqueous and ethanolic extracts of herbs for all antioxidant assays. Further study has been designed in our laboratory to identify the bioactive compounds responsible for the observed antioxidant and antimicrobial properties.

Biography :

Nurain Aziman was born in Johor, Malaysia in August 7, 1986. She receives B.Sc (2010) in Food Science and Technology from Universiti Teknologi MARA, Malaysia. She is currently postgraduate student (Ph.D) at Universiti Teknologi MARA in Food Science and Technology. Her research is focused on in vitro bioactivities of selected aromatic Malaysian herbs and their effects on the storage quality of Mechanically Deboned Chicken Meat (MDCM) product.