Microencapsulation of Mezcal Vinasse: Reduction of Undesirable Compounds Derived from the Production Process and Morphological Characterisation

Abstract

Mezcal vinasse contains potentially valuable compounds but also 5-(hydroxymethyl)furfural (HMF), which limits its utilization as a food ingredient. This study evaluated a sequential process comprising HMF mitigation with activated carbon and laccase under a central composite design, followed by corn starch microencapsulation through spray drying using a 15-run Box–Behnken design. The best observed HMF-treatment condition, consisting of 0.01 g activated carbon/100 mL, 873 µL laccase/100 mL, and pH 4.5, achieved a 76.69% HMF reduction while retaining 72.30% of the phenolic compounds. The quadratic HMF model showed R2 = 0.921 and adjusted R2 = 0.850. For microencapsulation, the best condition (140 °C inlet temperature, 50 V airflow, and 10 mL/min solution flow) produced the lowest water activity (0.1306), showed no resolvable low-temperature differential scanning calorimetry (DSC) endotherm, and exhibited comparatively smooth, low-defect morphology. Across the formulations, FTIR fingerprint-region correlations ranged from 0.9612 to 0.9996, and the first two principal components explained 91.1% of spectral variability. Median particle-domain diameter ranged from 4.331 to 5.808 µm, circularity from 0.556 to 0.599, and solidity from 0.837 to 0.864. Overall, the process reduced HMF while preserving phenolic compounds and produced a physically stabilized vinasse powder, allowing for a first step into the revalorization of mezcal vinasse.