Comparison of total phenolic content and antioxidant activities in selected coloured plants
ISSN: 0007-070X
Article publication date: 1 May 2020
Issue publication date: 5 October 2020
Abstract
Purpose
Literature has consistently reported that coloured plants are rich in dietary bioactive compounds. Therefore, this study aims to compare the total phenolic content and antioxidant activities in selected coloured plants (blue butterfly pea flower, roselle calyx, yellow bell pepper and purple sweet potato).
Design/methodology/approach
Total Phenolic Content (TPC) was determined using Folin–Ciocalteu assay, while antioxidant activities were evaluated using 2,2-dophenyl-1-picryl-hydrazyl-hydrate (DPPH) radical scavenging, Ferric Reducing Antioxidant Power (FRAP) and Trolox Equivalent Antioxidant Capacity (TEAC) assays.
Findings
TPC was reported from 273.15 ± 19.57 µg GAE/g DW (blue butterfly pea flower extract) to 363.10 ± 7.94 µg GAE/g DW (roselle calyx extract). Antioxidant activities as determined by DPPH assay ranged from 17.26 ± 0.06% (purple sweet potato extract) to 83.38 ± 1.04% (yellow bell pepper extract); while for FRAP assay was 4.92 ± 0.18 mg Fe (II)/g DW (purple sweet potato extract) to 128.33 ± 11.59 mg Fe (II)/g DW (roselle calyx extract). On the other hand, TEAC values were in the range of 15.26 ± 2.83 µg Trolox/g DW (roselle calyx extract) to 364.27 ± 7.14 µg Trolox/g DW (blue butterfly pea flower extract). A significant moderate positive correlation was observed between TPC and DPPH (r = 0.562) as well as TPC and FRAP (r = 0.686).
Originality/value
This study was the first to compare the total phenolic content and antioxidant activities in coloured plants. Findings derived from this study can be extended to the formulation of natural food colourants and nutraceuticals.
Keywords
Acknowledgements
The authors would like to extend the appreciation to everyone for the guidance during the project period.Conflicts of interest: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest (such as honoraria; educational grants; participation in speakers' bureaus; membership, employment, consultancies, stock ownership or other equity interest and expert testimony or patent-licensing arrangements), or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
Citation
Wong, P.Y. and Tan, S.T. (2020), "Comparison of total phenolic content and antioxidant activities in selected coloured plants", British Food Journal, Vol. 122 No. 10, pp. 3193-3201. https://doi.org/10.1108/BFJ-12-2019-0927
Publisher
:Emerald Publishing Limited
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