Quantification of Caffeine and Chlorogenic Acid in Green and Roasted Coffee Samples Using HPLC-DAD and Evaluation of the Effect of Degree of Roasting on Their Levels.

Shady Awwad,Reem Issa,Lilian Alnsour,Dima Albals,Idrees Al-Momani

doi:10.3390/molecules26247502

Abstract

Chlorogenic acid and caffeine are among the important components in coffee beans, determining the taste and aroma. In addition, phenols and antioxidants content possess vital health values. The main aim of this study is to determine the levels of caffeine and chlorogenic acid in several coffee samples of different origins and degrees of roasting. The coffee samples were extracted using hot water. The levels of caffeine and chlorogenic acid were quantified using high-performance liquid chromatography (HPLC) equipped with a diode array detector, a reverse phase system, and an ODS column (C18). Total phenol and antioxidant contents were previously determined for the same samples. The results showed that the highest content of caffeine was found in the medium roasted coffee (203.63 mg/L), and the highest content of chlorogenic acid content was found in the green coffee (543.23 mg/L). The results demonstrated a negative correlation between the chlorogenic acid levels with the degree of roasting, while it showed a positive correlation between the caffeine levels with the degree of roasting till a certain point where the levels dropped in the dark roasted coffee. The origin of coffee samples did not show any effect on any of the measured variables. Antioxidant effects of coffee samples were largely determined by chlorogenic acid content.

Highlights

Chlorogenic acids (CGAs), a group of phenolic esters of caffeic and ferulic acids, are found in many plants, fruits, and vegetables
Caffeine and CGA Content in Coffee Beans Based on Roasting Degree
The experimental results for the caffeine and CGAs analysis in coffee samples are presented in Supplementary Table S1

Summary

Introduction

Chlorogenic acids (CGAs), a group of phenolic esters of caffeic and ferulic acids, are found in many plants, fruits, and vegetables. They are reported to be found in high concentrations in coffee, as high as 70–350 mg per cup of coffee [1]. The biological importance of CGAs was studied throughout the years, demonstrating high antiviral, antidiabetic, antioxidant, and neuroprotective potential [1,2,3]. CGAs exhibit antioxidant and antiaging effects by enhancing cell proliferation, lowering lipid peroxidation, and accelerating wound healing, according to Chiang et al [4]

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Results