Sulforaphane Microcapsules via O/W Emulsion: Development, Characterization, and Application in Functional Yogurt

Sulforaphane (SFN) is an anti-cancer isothiocyanate occurring in Brassicaceae. SFN is decomposed by heat, oxygen, and alkaline conditions. Microencapsulation is a way to improve its stability. This work presents the development of SFN microcapsules using an oil-in-water emulsion with gum arabic (GA) as the wall material for incorporation into yogurt. The process for obtaining SFN microcapsules was optimized using response surface methodology. The optimal microencapsulation conditions were 7 min of stirring, an SFN/GA mass ratio of 0.7, and a surfactant concentration of 7%, resulting in an entrapment efficiency of 90.0 ± 3.0%, the highest reported. The microcapsules had a regular spherical shape with 0.5-5.5 µm diameter and no cracks. Freezing temperature (-4 °C) preserved 100% of SFN in the microcapsule for 90 days. Yogurt added with SFN microcapsules maintained physical and microbiological quality. SFN retention in yogurt after 30 days was 57% when microencapsulated, showing a 14-fold reduction in the kinetic degradation constant compared with free SFN, confirming the efficacy of this method.