Microencapsulation of the green coffee waste extract with high antioxidant activity by spray‐drying

Abstract

Currently, green coffee beans (GCB) are used in the food industry for oil extraction. 85% of which is discarded as a residue termed. Green coffee waste extract (GCWE). Which contains antioxidant compounds that have beneficial health effects. Antioxidant compounds are easily degraded and sensitive to various environmental conditions which can be combatted. Through microencapsulation, specifically through spray drying, which is widely used owing to its simplicity and low operating costs. The aim of this study was to evaluate the optimal concentration of wall materials for encapsulating GCWE. The characterization of GCWE by high-performance thin-layer chromatography (HPTLC) indicated that the extract was rich in chlorogenic acid with 21.78 mg/g representing 31.71% of the total phenols. Thereafter, a composite central design was conducted to determine the optimal concentrations of the wall materials (fructans and gum arabic); the best concentrations were 3% fructans and 2% gum arabic. The encapsulation process produced microcapsules with a 94.36% encapsulate efficiency and a 27.45% (18.86 mg/g) concentration of chlorogenic acid. In conclusion, we evaluated the effect of wall material concentration and determined the optimal parameters of spray drying to protect the GCWE. Novelty Impact Statement Spray-drying microencapsulation using agave fructans and gum arabic as wall material showed an encapsulation efficiency higher than 90%, which allows preserving the antioxidant compounds present in the green coffee residue extract.