THE USE OF LOW-INTENSITY PULSED ELECTRIC FIELDS ENHANCES VITAMIN D MICROENCAPSULATION IN RESIDUAL BREWER’S YEAST

Vitamin D₃ is a hormone responsible for regulating serum calcium and phosphorus concentrations and maintaining bone health. Low intake of vitamin D-rich foods, metabolic disorders, or gastrointestinal problems are factors that may exacerbate vitamin D deficiency. Residual brewer’s yeast (RBY) is a by-product of the brewing industry that is often discarded due to its loss of functional value. The use of RBY for vitamin encapsulation represents a novel approach with considerable potential for exploration, and electroporation-based encapsulation has emerged as a promising alternative. Electroporation is a process that induces pore formation in the cell membrane by applying pulsed electric fields (PEF). PEF treatment involves the application of high-voltage electric pulses at short intervals, resulting in structural alterations of the plasma membrane and increased cell permeability. The main objective of this study was to investigate electroporation conditions for vitamin D₃ accumulation in RBY using a low-voltage PEF technique. The RBY biomass was previously decontaminated and inactivated by thermal treatment (121 °C for 10 min). The PEF system and treatment chamber, equipped with tin electrodes (conductive electrodes) and copper electrodes coated with heat-shrinkable polyolefin polymer (non-conductive electrodes), were designed and developed by the Laboratory of Applied and Computational Physics (LAFAC – FZEA – USP). An ethanolic solution of vitamin D₃ (100 µg/mL) was mixed with 100 mg of RBY dry matter. Samples were subjected to agitation at 1500 rpm for 30 minutes, both before and after exposure to an electric field (100 V, 100 Hz) for 2.5, 5, and 15 minutes, respectively. Vitamin D concentration was then quantified using a UV–VIS spectrophotometric method at 275 nm. Three independent treatments were performed in duplicate. The results indicated that the highest vitamin D incorporation into RBY occurred after 2.5 minutes, reaching 54.22% and 52.86% using conductive and non-conductive electrodes, respectively. These findings demonstrate the potential of low-voltage PEF technology for the microencapsulation of bioactive compounds.