Optimization of Extraction Conditions For Phenolic Antioxidants From The Peels of Limau Purut (Citrus Hystrix)

Author

Chan S.W. & Ho C.W      
Food Science and Nutrition, Faculty of Applied Sciences, University College Sedaya International (UCSI), No. 1 Jalan Menara Gading, UCSI Heights, Cheras 56000, Kuala Lumpur.   
Tel: 03-9101-8880  Fax : 03-9102-3606  Email: This email address is being protected from spambots. You need JavaScript enabled to view it.

Language

English

Title

Optimization of Extraction Conditions For Phenolic Antioxidants From The Peels of Limau Purut (Citrus Hystrix)

Proceeding

Medicinal and Aromatic Plants Seminar (MAPS 2008)

Date

21st October - 22nd October 2008

Place Held

The Legend Hotel, Kuala Lumpur

Abstract

'Limau purut' (Citrus hystrix) is a tropical herb that is commonly found in Malaysia and many other Southeast Asian countries. The juice and leaves of 'limau purut' are popularly used as food condiments in the Southeast Asian region. However, the peels are often discarded. Indeed, 'limau purut' peels are very rich in phenolic compounds which are extractable as natural antioxdidants or functional food ingredients. In this work, the extraction conditions for phenolic antioxidants from 'limau purut' peels were optimized using response surface methodology (RSM). A rotatable central composite design (CCD) was applied to investigate the effects of ethanol concentration (%), extraction temperature (ºC) and extraction time (minutes) on total phenolic content (TPC), 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power of 'limau purut' peel extracts. The independent variables were coded at five levels and their actual values were selected based on the resultsof single factor experiments. The results showed that ethanol concentration was the most significant (P<0.01) factor affecting all the responses. The highest TPC was reached at ethanol concentration of 52.93%, extraction temperature of 48.32ºC, and extraction time of 126.49 minutes. On the other hand, the optimal extraction conditions for DPPH radical scavenging activity and reducing power were found to be 77.69% ethanol, 31.08ºC, 126.49 minutes and 75.56 % ethanol, 33.25ºC, 146.97 minutes, respectively. Under the optimized conditions, the experimental values for TPC, DPPH radical scavenging activity and reducing power were 1291.84mg GAE/100g DW, 82.86% and 21.86.36mg GAE/100g DW which were reasonably close to the predicted values. This indicated the suitability of the model and the successfulness of RSM in optimizing the extraction conditions for phenolic antioxidants from 'limau purut' peels.

Keywords

Citrus hystrix; limau purut peel; natural antioxidants; phenolic; response surface methodology

Session

Plenary: Session 3

Topic

Think Global, Act Local: A New Paradigm In Malaysian Herbal Industry (Prof. Emeritus Dr. Abdul Latif Ibrahim-UNISEL)