Assessing the effect of cold plasma pretreatment on the quality characteristics of bioactive compound extraction from high-pressure processing treated green coffee beans

Abstract

This study presents a novel approach for enhancing the extraction efficiency of bioactive compounds from green coffee beans (Coffea arabica) by combining cold plasma pretreatment with high-pressure processing (HPP). Traditional extraction methods often result in the degradation of bioactives and raise environmental concerns. Cold plasma, a non-thermal technology, modifies plant cell walls to increase permeability, facilitating the release of valuable compounds. When integrated with HPP, which uses hydrostatic pressure to further enhance extraction, the combination proves highly effective. Optical Emission Spectroscopy (OES) was used to characterize plasma-generated reactive species interacting with the coffee bean surfaces, improving extraction yield. Significant improvements were observed in total phenolic content (TPC), radical scavenging activity, chlorogenic acid (CGA), and caffeine levels. Notably, the highest extraction yield (16.682 mg/mL) was achieved with 300 MPa HPP for 30 min without cold plasma. Cold plasma pretreatment increased TPC to 18.661 mg/mL (5 min of cold plasma and 300 MPa HPP for 10 min), and radical scavenging activity reached up to 96.845 %. This combined treatment also led to enhanced CGA content

(10.294 mg/mL). The Gas Chromatography-Mass Spectrometry (GC–MS) analysis revealed significant changes in the composition and concentration of secondary metabolites, such as caffeine and phenolic derivatives. Gas Chromatography-Mass Spectrometry (GC–MS) analysis revealed significant changes in the composition and concentration of secondary metabolites, such as caffeine and phenolic derivatives. This study demonstrates the novel and promising potential of cold plasma-assisted HPP for producing high-quality, bioactive-rich extracts from green coffee beans, with considerable advantages over conventional extraction methods in terms of bioactive preservation and extraction efficiency. The approach holds significant potential for applications in the food, beverage, and nutraceutical industries.