Antioxidant activities, total polyphenol and vitamin C contents of local fruits from Sabah

Lee, Kian Hung (2007) Antioxidant activities, total polyphenol and vitamin C contents of local fruits from Sabah. Universiti Malaysia Sabah. (Unpublished)


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The objective of this study was to determine the antioxidant activities, total polyphenol and vitamin C contents of ten local fruits from Sabah. The correlations between antioxidant activity (measured by DPPH and FRAP assays) with total polyphenol and vitamin C contents were investigated. The antioxidant activities were evaluated based on the ability of the nine fruit extracts to scavenge 1, 1-diphenyl-2- picrylhdrazyl (DPPH) and ferric reducing antioxidant power (FRAP). The total polyphenol contents of the local fruits were measured by Folin-Ciocalteau assay and vitamin C contents were determined by 2, 6-dicloroindophenol titrimetric method (AOAC, 2000). The results showed that the fruits, bambangan and salak had significant higher (p < 0.05) primary antioxidant potential than the rest of the fruits studies, as measured by DPPH and FRAP assays. Besides that the other fruits, canistel, star fruit, tarap, guava and mango were also considered to give high antioxidant activities assessed by DPPH and FRAP assays. Data obtained showed that bambangan, salak and tarap contained higher total polyphenol contents as compared to the other fruit extracts. Furthermore, guava, bambangan, papaya, star fruit and mango showed higher vitamin C contents as compared to the others fruits. The local fruits in this study exhibited significant positive and linear correlations (R = 0.870, p< 0.01) between DPPH and FRAP assays. This study showed that the local fruits possessed significant free radical scavenging and reducing power ability in vitro. Both antioxidant assays showed significant positive correlations with total polyphenol contents expressed as gallic acid eqUivalents, but had weak correlations with vitamin C contents. Hence, the results clearly indicated that vitamin C was not the main constituents in these fruits and polyphenol compounds are mainly responsible for the antioxidant activity observed. Bambangan and salak can be considered as potentially excellent sources of natural antioxidants in the human diet.

Item Type: Academic Exercise
Uncontrolled Keywords: antioxidant, polyphenol, vitamin C, local fruits, Sabah
Subjects: T Technology > TX Home economics > Nutrition. Foods and food supply
Divisions: SCHOOL > School of Food Science and Nutrition
Date Deposited: 21 May 2013 02:58
Last Modified: 13 Oct 2017 08:56

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