This study proposes the investigation of curcumin encapsulation into Saccharomyces cerevisiae cells through osmoporation as an efficient way of increasing curcumin stability. The influence of three process parameters (cell, ethanol and curcumin concentrations) on the encapsulation process was evaluated, and the obtained biocapsules were characterised for physical and photochemical stabilisation. Results showed that encapsulation efficiency was favoured by the increase of cells/curcumin ratio and ethanol concentration up to 60%. Differential scanning calorimetry (DSC) curves revealed that yeast encapsulation delayed the curcumin melting point up to 207 °C. Encapsulated curcumin retained over 80% of antioxidant activity after thermal treatment (150 °C) and over 70% after a 50-day exposure to artificial light. Photochemical stability of yeast-encapsulated curcumin was increased by 5.7-fold, and half-life time reached 181 days under illumination conditions. Overall, osmoporation-produced yeast biocapsules confirmed the versatility of osmoporation as an encapsulation technique and successfully improved curcumin stability.
Keywords: Antioxidant activity; Curcumin; Microencapsulation; Osmoporation; S. cerevisiae; Stability.