Riboflavin Phototransformation on the Changes of Antioxidant Capacities in Phenolic Compounds

Abstract

Eight phenolic compounds including: p-coumaric acid, vanillic acid, caffeic acid, chlorogenic acid, trolox, quercetin, curcumin, and resveratrol were treated with riboflavin (RF) photosensitization and in vitro antioxidant capacities of the mixtures were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2' azino bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Mixtures containing p-coumaric acid and vanillic acid under RF photosensitization showed increases in ferric ion reducing ability and radical scavenging activity of DPPH, whereas mixtures of other compounds had decreases in both radical scavenging ability and ferric reducing antioxidant power. Hydroxycoumaric acid and conjugated hydroxycoumaric and coumaric acids were tentatively identified from RF photosensitized p-coumaric acid, whereas dimmers of vanillic acid were tentatively identified from RF photosensitized vanillic acid. RF photosensitization may be a useful method to enhance antioxidant properties like ferric ion reducing abilities of some selected phenolic compounds.

Photooxidation of phytochemicals in food and control: a review

“…When treated with the RF model, hydroxycoumaric acid and conjugated hydroxycoumaric and coumaric acids were tentatively identified as p ‐coumaric acid photosensitized products, whereas dimers of vanillic acid were tentatively identified from RF‐photosensitized vanillic acid. After being photosensitized by RF, p ‐coumaric acid and vanillic acid showed increased activity in DPPH and fluorescence recovery after photobleaching (FRAP) assays, whereas caffeic acid, chlorogenic acid, and curcumin decreased in all three assays . This finding suggests that RF photosensitization may be a useful method to enhance the antioxidant activity of some typical phenolic acids.…”

“…For example, RF phototransformation of genistein derivatives can enhance antioxidant activities in isoflavone aglycones . The radical scavenging ability of p ‐coumaric acid and vanillic acid also increased in DPPH and FRAP assays, possibly because of the formation of new oxidizable hydroxyl groups in polymeric products by polymerization, thereby resulting in higher free radical scavenging activity . In addition, many flavonoid dimers are naturally present in fruits, vegetables, or their products, such as procyanidins, which have a positive effect on human health.…”

Biopolymer-solid lipid hybrid microparticles as a nutraceutical co-delivery carrier in the gastrointestinal tract

“…Quercetin has been shown to have a better effect and enhanced bioavailability in the presence of riboflavin [7,8]. This gives rise to the idea of co-encapsulating these two bioactive compounds in the newly developed biopolymer-solid lipid hybrid microparticles to elicit the synergistic action in order to enhance the bioavailability and increase the intestinal absorption.…”

“…or singlet oxygen generated from triplet oxygen (type II pathway) [8]. It is believed that the photosensitization of riboflavin by the additional hydroxyl groups can enhance the antioxidant property of phenolic compounds [8].…”

“…or singlet oxygen generated from triplet oxygen (type II pathway) [8]. It is believed that the photosensitization of riboflavin by the additional hydroxyl groups can enhance the antioxidant property of phenolic compounds [8]. Therefore, this fact leads to the idea of encapsulating riboflavin together with quercetin, which can increase the antioxidant effect of quercetin, and deliver riboflavin concurrently in the same system.…”