Co-encapsulation of E. faecium E297 and γ-aminobutyric acid (GABA): resilience to adverse conditions and application in oat flakes to enhance its functional properties.

The study evaluated the effectiveness of co-encapsulating E. faecium E297 and γ-aminobutyric acid (GABA), as well as their resilience to adverse conditions during processing, storage, and simulated gastrointestinal digestion, aiming at their application in oat flakes to enhance their functional properties. Initial hydrophobicity and cultivation tests indicated that E. faecium E297 strongly adheres to intestinal cells and that GABA does not interfere with the microorganism's viability. Double emulsion (W₁/O/W₂) encapsulation demonstrated high efficiency, with retention rates of 88.10 ± 0.65% for the probiotic and 90.23 ± 0.16% for the bioactive compound. The generated microcapsules (10-20 μm) protected the compounds against thermal treatment (65 °C for 30 min) and storage (25 °C for 30 days), ensuring concentrations above 6.0 log CFU/mL of E. faecium E297 and 58 mg/mL of GABA. During gastrointestinal simulation, encapsulated E. faecium E297 exhibited greater resistance (7.83 ± 0.07 log CFU/g) compared to the unencapsulated form (5.06 ± 0.07 log CFU/mL), while GABA maintained its stability under gastric conditions. When incorporated into oat flakes and stored at 25 °C for 30 days, both forms of the microorganism showed a reduction in count. However, E. faecium E297 remained significantly more concentrated in the encapsulated form, maintaining levels above 7.0 log CFU/g, while GABA concentration was 8.86 ± 0.60 mg/g. These findings highlight that co-encapsulation of E. faecium E297 and GABA, combined with their application in oat flakes, ensures efficient compound delivery and may enhance the health benefits of this functional food.