Dietary Antioxidants in Coffee Leaves: Impact of Botanical Origin and Maturity on Chlorogenic Acids and Xanthones.

Ângelo Monteiro,Silvia Colomban,Marina Resmini,Leonor Guerra-Guimarães,Luciano Navarini,Maria Do Céu Silva,Helena G Azinheira

doi:10.3390/antiox9010006

Abstract

Natural polyphenols are important dietary antioxidants that significantly benefit human health. Coffee and tea have been shown to largely contribute to the dietary intake of these antioxidants in several populations. More recently, the use of coffee leaves to produce tea has become a potential commercial target, therefore prompting studies on the quantification of polyphenols in coffee leaves. In this study a variety of coffee leaf species, at different development stages, were analyzed using ultra-high pressure liquid chromatography. The results demonstrate that both the botanical origin of the samples and their maturity influence significantly the concentration of the antioxidants; for total chlorogenic acids a two-fold difference was found between different species and up to a three-fold variation was observed between young and mature leaves. Furthermore, the range of concentrations of chlorogenic acids in young leaves (35.7–80.8 mg/g of dry matter) were found to be comparable to the one reported for green coffee beans. The results provide important data from which potential new commercial products can be developed.

Highlights

Natural polyphenols, one of the most important groups of dietary antioxidants, include a wide variety of chemical compounds, such as flavones, flavonols, isoflavones, and phenolic acids, including chlorogenic acids (CGAs) [1]
The use of ultra-high-performance liquid chromatography (UHPLC)-diode array detector (DAD) in this work has allowed to complete the analysis of each run in 14 min, considerably improving the length of time require for this analysis, and decreasing the limit of detection
The present study reports the content of a number of bioactive compounds abundant in four different coffee leaf species at different development stages: C. arabica, C. canephora, C. eugenioides, and C. racemosa

Summary

Introduction

One of the most important groups of dietary antioxidants, include a wide variety of chemical compounds, such as flavones, flavonols, isoflavones, and phenolic acids, including chlorogenic acids (CGAs) [1]. All these secondary metabolites are widely found in fruits, vegetables, grains, and cocoa, as well as coffee, tea, and wine [2]. These phytochemicals are of great interest to nutritionists, food scientists and consumers due to their demonstrated impact on human health, especially in the prevention of degenerative and cardiovascular diseases, and metabolic disorders [3].

Methods

Results

Conclusion