Phenolic antioxidants

identified by ESI-MS from Yerba mate
(Ilex paraguariensis) and green tea (Camelia sinensis) extracts

The content published on this website comes from the National Library of Medicine and has been translated into English.

Link to source – https://pubmed.ncbi.nlm.nih.gov/17851401/

Abstract

Aqueous extracts of green yerba mate (Ilex paraguariensis) and green tea (Camellia sinensis) are a good source of phenolic antioxidants, as already described in the literature. The subject of the research were organic extracts from both green and roasted yerba mate, as well as from green tea. Their phenolic profiles were characterised using electrospray ionisation mass spectrometry with direct infusion (ESI-MS), and their free radical scavenging activity was determined using the DPPH assay. Organic extracts containing phenolic antioxidants can be used as natural antioxidants in the food industry, replacing the synthetic phenolic additives currently in use. Ethanolic and aqueous extracts of green yerba mate, roasted yerba mate and green tea showed excellent DPPH scavenging activity (>89%). Ether extracts of green and roasted yerba mate showed weak scavenging activity, different from the behaviour observed for the ether extract of green tea. The main phenolic compounds identified in the water and ethanolic extracts of green yerba mate were: caffeic acid, quinic acid, caffeoylglucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process, two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. Ethanolic extracts of yerba mate, both roasted and green, with a lower content of phenolic compounds (3.80 and 2.83 mg/mL) showed high antioxidant activity, and even at very low phenol concentrations, the ether extract of GT (0.07 mg/mL) inhibited DPPH by more than 90%. The main phenolic compounds identified in the water and ethanolic extracts of green yerba mate were: caffeic acid, quinic acid, caffeoylglucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process, two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. Ethanolic extracts of yerba mate, both roasted and green, with a lower content of phenolic compounds (3.80 and 2.83 mg/mL) showed high antioxidant activity, and even at very low phenol concentrations, the ether extract of GT (0.07 mg/mL) inhibited DPPH by more than 90%. The main phenolic compounds identified in the water and ethanolic extracts of green yerba mate were: caffeic acid, quinic acid, caffeoylglucose, caffeoylquinic acid, feruloylquinic acid, dicaffeoylquinic acid and rutin. After the roasting process, two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. Ethanolic extracts of yerba mate, both roasted and green, with a lower content of phenolic compounds (3.80 and 2.83 mg/mL) showed high antioxidant activity, and even at very low phenol concentrations, the ether extract of GT (0.07 mg/mL) inhibited DPPH by more than 90%. After the roasting process, two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. Ethanolic extracts of yerba mate, both roasted and green, with a lower content of phenolic compounds (3.80 and 2.83 mg/mL) showed high antioxidant activity, and even at very low phenol concentrations, the ether extract of GT (0.07 mg/mL) inhibited DPPH by more than 90%. After the roasting process, two new compounds were formed: caffeoylshikimic acid and dicaffeoylshikimic acid. Ethanolic extracts of yerba mate, both roasted and green, with a lower content of phenolic compounds (3.80 and 2.83 mg/mL) showed high antioxidant activity, and even at very low phenol concentrations, the ether extract of GT (0.07 mg/mL) inhibited DPPH by more than 90%.

Figures

The content published on this website comes from the National Library of Medicine and has been translated into English.

Link to source – https://pubmed.ncbi.nlm.nih.gov/17851401/