Microencapsulation of Essential Oil from Campomanesia adamantium Residue with Antioxidant Capacity Retention

Abstract

The essential oil (EO) extracted from the peels and seeds of guavira (Campomanesia adamantium) was microencapsulated via complex coacervation between gelatin and gum arabic, followed by freeze-drying. This process aimed to reduce the volatility of the essential oil and protect bioactive compounds through the microcapsule wall. For process optimization, the influence of proportions of wall materials (gelatin: gum arabic ratios of 1:1, 1:2, 1:3, 2:1, and 3:1) and EO quantity (20% - 42.8%) on antioxidant capacity, morphology, and microencapsulation yield was measured using a central composite rotational design (CCRD). Additionally, the chemical composition and EO retention rate in the microcapsules were assessed. Gelatin: gum arabic ratio of 1:2 and EO quantity of 40.3% resulted in superior results, with the highest antioxidant capacity, a microencapsulation yield of 68%, and spherical morphology. Notably, the incorporation of a higher amount of EO led to an increase in the antioxidant capacity, with values reaching up to 99% equivalent to pure oil. All formulations maintained the same pure EO’s main constituents, including α-pinene, limonene, β-ocimene, and β-caryophyllene, indicated by gas chromatography coupled to mass spectrometry. Consequently, for the first time, EO microcapsules were successfully obtained from guavira residue, showing high microencapsulation yield and EO retention. This achievement adds sustainable value to residue normally discarded, which enables better use of residue generated by the food industry. Due to the preservation of its antioxidant capacity and enhanced retention of volatile compounds, these microcapsules promise applications in the food, pharmaceutical, and cosmetic industries, aligning with sustainability principles.