Purification of Coffee Polyphenols Extracted from Coffee Pulps (Coffee arabica L.) Using Aqueous Two-Phase System

Area of Science:

• Food Science
• Biochemistry
• Chemical Engineering

Background:

• Coffee pulp is a rich source of polyphenols, but conventional extraction methods yield impure products.
• Polyphenols possess significant antioxidant properties valuable for various applications.
• Impure extracts limit the efficacy and usability of coffee pulp-derived compounds.

Purpose of the Study:

• To develop an efficient purification method for polyphenols from coffee pulp.
• To evaluate the impact of purification on total polyphenol content and antioxidant activity.
• To identify and quantify major polyphenols like chlorogenic acid and caffeic acid in the purified extract.

Main Methods:

• Application of an aqueous two-phase system (ethanol/ammonium sulfate) for polyphenol extraction and purification.
• Quantification of total polyphenol content using spectrophotometric methods.
• Assessment of antioxidant activity via established assays.
• Analysis of specific polyphenols (chlorogenic acid, caffeic acid) using chromatography.
• Fourier-transform infrared spectroscopy (FTIR) for impurity profiling.

Main Results:

• Phenolic compounds were predominantly partitioned into the alcohol-rich phase of the two-phase system.
• Purified coffee pulp extract exhibited a significant increase in antioxidant activity (approx. 34%) compared to the crude extract.
• A slight increase in chlorogenic acid and caffeic acid content was observed in the purified samples.
• FTIR analysis confirmed the removal of several impurities during the purification process.

Conclusions:

• The aqueous two-phase system is an effective method for purifying polyphenols from coffee pulp.
• Purification enhances the antioxidant potential of coffee pulp extracts by concentrating beneficial compounds and removing impurities.
• This method offers a promising approach for valorizing coffee industry by-products into high-value ingredients.