Optimization of extraction process and effect of cooking methods on antioxidant activities of wild edible mushroom, Pleurotus porrigens

Lim , Yock Ea (2009) Optimization of extraction process and effect of cooking methods on antioxidant activities of wild edible mushroom, Pleurotus porrigens. Universiti Malaysia Sabah. (Unpublished)

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Abstract

The optimum conditions for the extraction of mushroom extract were determined using Response Surface Methodology (RSM). A central composite rotatable design (CCRD) was used to investigate the effect of the these three independent variables, namely solvent composition (%), extraction temperature (0C) and time (h) on the response, inhibition activity of DPPH free radical, inhibition of lipid peroxide, inhibition of ABTS radical cation, ferric reducing power and the total yield of extract. 20 experimental points have been generated with six replications at center point. Data were analyzed using design expert and statistical analysis system software. A second-order polynomial was used for predicting the response. The results showed that the optimum conditions for the antioxidant activities obtained were 70.25%, 55°C, 2h with the desirability of 0.715. Under these conditions, the experimental predicted yield was 16.55 %, inhibition of DPPH radical was 88.36%, inhibition of lipid peroxide was 94.58%, inhibition of ABTS radical was 0.218 mM TE/mg extract, and ferric reducing power was 164.44 uM Fe(ll)/mg extract. As for cooking effects, the results showed that boiling for 5 minutes showed the best indication in DPPH assay. This could be due to the destruction of cell walls and sub-cellular compartments of mushroom during the boiling causes the release of potent radical inhibition antioxidants. In contrary, stir-frying gives the marked (P<0.05) high activities in other assays. The good stir-frying effects revealed in ABTS and FRAP assays were due to the higher extraction yield obtained raw mushroom. However, another possible reason was the inactivation of the polyphenol oxidase enzyme during heating, leading to the inhibition of polyphenols degradation.

Item Type: Academic Exercise
Uncontrolled Keywords: Extraction of Mushroom, Response surface methodology (RSM), Mushrooms, Pleurotus porrigens, antioxidant, Wild mushroom
Subjects: ?? TX642-840 ??
Divisions: SCHOOL > School of Food Science and Nutrition
Depositing User: Unnamed user with email storage.bpmlib@ums.edu.my
Date Deposited: 08 Nov 2011 08:26
Last Modified: 08 Nov 2011 08:26
URI: http://eprints.ums.edu.my/id/eprint/753

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