Fruit red colorants impact on the antiradical activity determined by DPPH method

Abstract

This work is focused on the determination of antiradical activity (ARA) by the method of free radical scavenging of 2,2-Diphenyl-1-picrylhydrazyl (DPPH). Since the DPPH solution is intense purple-coloured and absorbs at a wavelength of 517 nm, similar to the anthocyanin colorants of fruits, the modification of the method examined the effect of the colour of the sample extracts on the result of the ARA determination. Statistical evaluation of the results of the analyses using Youden's graphing method revealed that the two compared method adjustments gave consistent results over the observed range of antiradical activity. It also showed that there was no statistically significant difference between the mean ARA values obtained by the two treatments. Investigation of the effect of the evaluated fruit components revealed a strong correlation between the content of ascorbic acid and ARA in samples containing no anthocyanin colorants. For the fruit samples studied, ARA values showed a strong correlation with polyphenol content.

Increased radical scavenging activity of thymoquinone and l-ascorbic acid dual encapsulated in palmitoyl-chitosan nanoparticles in a human normal lung fibroblast, MRC-5 due to synergistic antioxidative effects

“…The reduction reaction of the DPPH radical took place when it received hydrogen from the antioxidant(s), resulting in the formation of DPPH-H (non-radical) and changed its color from purple to yellow. 17,19,56 Based on the EC 50 values, the DPPH scavenging activity shown by LAA was higher than TQ because TQ has a lower capacity of work as antioxidant hydrogen or electron donors. 52 LAA is reported to scavenge DPPH radicals in MeOH by a hydrogen transfer reaction to form DPPH-H. 18 Some studies reported that the EC 50 value of LAA was around 20 mM for the DPPH assay.…”