1.Determination of Daidzein and Genistein Contents in Mangifera Fruit
Malaysian Journal of Nutrition 2008;14(2):189-198
The aim of this study was to determine the daidzein and genistein contents in Mangifera fruits. Three Mangifera species namely ‘bacang’ (Mangifera foetida), ‘kuini’
(M. odorata) and ‘bambangan’ (M. pajang) each from two different locations were selected. The extraction of isoflavones was carried out at 80oC for 30, 60 and 90
min. HPLC method was performed with a flow rate of 1.00 ml/min using three different separation columns to determine isoflavone contents. The Zorbax
Eclipse RP C18 reverse-phase column was found to give the best resolution for isoflavone separation in Mangifera fruits. Moreover, extraction time of 90 min
was found to increase the isoflavone aglycone contents. At optimised condition, ‘kuini’ had relatively high daidzein (9.4-10.5 mg/100 g) and genistein (1.6-1.7
mg/100 g) contents. Daidzein content of ‘bambangan’ (8.3-8.7 mg/100 g) was higher than ‘bacang’, but the genistein content of ‘bambangan’ (0.4-0.6 mg/100
g) was similar to that of ‘bacang’ (0.4-0.8 mg/100 g). However, there was a variation in daidzein and genistein contents in Mangifera fruits between two
geographical locations.
2.Antioxidative Properties of an Extract of Hygrocybe conica, a Wild Edible Mushroom
Chong EL ; Sia CM ; Khoo HE ; Chang SK ; Yim HS
Malaysian Journal of Nutrition 2014;20(1):101-111
Hygrocybe conica (HC), a wild mushroom commonly consumed by the indigenous people (Orang Asti) in Peninsular Malaysia, was assessed for its antioxidant content. Methods: The HC mushroom was extracted using distilled water and the crude extract partitioned using different solvents and open column chromatography to evaluate its potential antioxidant properties. The mushroom extract was partitioned using liquid-liquid extraction into the hexane (F1), chloroform (F2), butanol (F3) and formic acid (F4) fractions. Based on solvent polarity, the water extract of the mushroom was fractionated into non-polar (FI), semi-polar (FII), and polar fractions (FIII) using open column chromato�graphy. Antioxidant capacities were determined using DPPH, ABTS, and ferric reducing antioxidant power (FRAP) assays while Folin-Ciocalteu reagent assay was used to determine total phenolic content (TPC). Results: The HC extract had the highest TPC and DPPH scavenging capacity compared to its extract fractions. TE values (ABTS assay) of F2 and F4 were not significantly higher than the HC extract. Among the extract fractions of different polarities, FIII had the highest antioxidant capacities (DPPH and FRAP) compared to FI and FII while FRAP values of these fractions were not significantly lower than the FRAP value of HC extract. The HC extract had significantly lower antioxidant capacity than antioxidant standards (ascorbic acid and BHA). Tannic acid as the main bioactive component in HC mushroom was detected using HPLC method. The presence of phenolics in HC extract was also confirmed using TLC. Conclusion: Due to the presence of potent phenolic components, the mycelia of HC could be consumed for potential antioxidative benefits.
Antioxidants
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Agaricales