Simultaneous Extraction and Decaffeination Process Optimization of Green Coffee Bean-Based Beverages Using Response Surface Methodology

Abstract

Coffee is a popular drink worldwide, but some people cannot consume it due to its high caffeine content. However, it contains chlorogenic acid, which benefits the human body. To reduce the caffeine content and maintain phenolic compounds, especially chlorogenic acid and its derivatives in green coffee beans, a simultaneous extraction and decaffeination method using hot water was used. Box Behnken Design-Response Surface Methodology was used in this study to determine the optimum simultaneous extraction and decaffeination process for obtaining minimum caffeine and maximum phenolic and antioxidant activity (IC50) of the decaffeinated green coffee bean powder. The Design Expert software was used to analyze and optimize process parameters. Analysis of Variance (ANOVA) test was conducted to identify significant parameters. Three independent parameters were used, i.e., extraction time (10 to 30 min), decaffeination time (6 to 10 h), and decaffeination temperature (60 to 80 °C), to observe the 3 responses (caffeine content, phenolic content, and IC50). The result revealed that the extraction and decaffeination parameters affected green coffee bean powder-based beverages’ caffeine content, total phenolic, and IC50. The lowest caffeine, the highest phenolic, and IC50 were predicted at an extraction time of 10 min, decaffeination time of 8.05 h, and decaffeination temperature of 60 °C with a caffeine content of 1.53 %, total phenolic content of 46.81 mg GAE/g, and IC50 of 29.45 ppm, respectively. The verification showed no significant difference with model predictions at a confidence interval of 5 % based on paired t-tests. HIGHLIGHTS The simultaneous extraction and decaffeination process using hot water successfully produces green coffee bean-based beverages with low caffeine content The extraction and decaffeination parameters affected the caffeine, total phenolic, and antioxidant activity of green coffee bean-based beverages The optimum conditions for the extraction and decaffeination process using hot water were revealed GRAPHICAL ABSTRACT