Effect of extraction and drying methods on antioxidant activity of Limnophila aromatica

Ng, Seah Young (2009) Effect of extraction and drying methods on antioxidant activity of Limnophila aromatica. Universiti Malaysia Sabah. (Unpublished)

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Abstract

The sintata (Limnophila aromatica) plant was used locally to treat fever and consumed as vegetable. It was known to contain large amount of flavonoids and phenolic compounds. It was also a promising source of antioxidant activity. Effect of various drying methods, types of extraction solvent, solvent to water ratio, extraction time, temperature and sample to solvent ratio on antioxidant activity were tested. The antioxidant assay used were DPPH and β-carotene bleaching inhibition assay expressed in mg/ml of EC50; FRAP assay expressed in mmol/g of Fe²+; and ABTS assay expressed in TEAC value in µmol/I-lg. It was found that sample dried in oven at 40°C, extracted by using ethanol as solvent could obtain high antioxidant activity. Extraction variables of 18 hours at 30°C, ethanol to water ratio of 60% and sample to solvent ratio of 1:20 were chosen as mean for optimizing the yield and antioxidant activity by response surface methodology using central composite design. Extract with high antioxidant activity was found extracted by Ethanol to water ratio of 1:71.08, 25 hours of extraction time and sample to solvent ratio of 1:19.98. Under these conditions, the estimated l/EC50 value for DPPH assay was 1.997 mg/ml. Estimated Fe²+ value for FRAP assay was 3214.51 mmol/mg, TEAC value for ABTS assay was 191.311 µmol/µg, l/EC50 of β-carotene bleaching assay was 1.958 mg/ml and extraction yield of 23.694%.

Item Type: Academic Exercise
Uncontrolled Keywords: Sintata, Limnophila aromatica, Antioxidant activity, Flavonoids, Phenolic, Fever treatment
Subjects: T Technology > TX Home economics > Nutrition. Foods and food supply
Depositing User: Unnamed user with email storage.bpmlib@ums.edu.my
Date Deposited: 02 May 2012 10:01
Last Modified: 23 Oct 2017 03:30
URI: http://eprints.ums.edu.my/id/eprint/3990

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