Obtaining coffee mucilage microcapsules by spray drying using chemically modified banana starch

The growing global consumption of coffee has positioned Colombia as the third largest producer worldwide. However, the processing of coffee beans generates significant by-products, such as mucilage, which is rich in phenolic compounds with antioxidant activity. Inadequate disposal of this waste creates environmental problems and economic losses. This research aimed to develop high-quality coffee mucilage capsules using spray drying technology. Chemically modified banana starch with octenyl succinic anhydride (OSA) and commercial maltodextrin were used as coating materials to enhance the properties of the capsules. Physicochemical and functional characterization was performed on samples of fresh and filtered coffee mucilage (MF), concentrated mucilage (MC), concentrated mucilage with the addition of maltodextrin and OSA-modified starch (MCMA), and finally, spray-dried coffee mucilage powder (MP). The antioxidant capacity (AC) of the mucilage was evaluated throughout the processing stages. MF showed an AC of 179.2 µmol of trolox/100 g, while the final coffee mucilage powder (MP) showed a significantly higher AC of 5444.35 µmol of trolox/100 g. Additionally, the MP showed a stability index of 0.48, water activity (aw) of 0.19, solubility of 14.64%, and a high water retention capacity of 90.53%. Microscopic analysis revealed amorphous structures with an average size of 29.16 ± 2.12 µm in the MP. These findings highlight the potential of spray drying with food-grade matrices such as OSA-modified banana starch to encapsulate coffee mucilage, preserving its antioxidant capacity and creating a new functional food ingredient with water retention properties.