ABSTRACT
The delivery of active probiotic cells in capsules can reduce probiotic cell loss induced by detrimental external factors during digestion. In this study, we determined the optimal conditions for the encapsulation of Weissella cibaria JW15 (JW15) within calcium and polyethylene glycol (PEG)-alginate with chicory root extract powder (CREP). JW15 was encapsulated as the core material (109 cells/mL, 2 mL/min), and a solution containing a mixture of 1.5% sodium alginate and 1% CREP was extruded into a receiving bath with 0.1 M calcium chloride (CaCl2 ) and 0.05% PEG. Capsule morphology and size were measured using optical microscopy. The optimal air pressure and frequency vibration for capsules containing alginate only (Al) were 200 mbar and 200 Hz, respectively and 100 mbar and 350 Hz for capsules containing alginate with CREP (Ch), respectively. The voltage for both capsules types was fixed at 1.35 kV. Then, the capsules were incubated in a simulated gastrointestinal (GI) system for 6 hr at 37 °C. The addition of PEG in a CaCl2 hardening solution led to degradation of the Ch capsule (Ch-PEG) and the release of cells into the small intestine vessel in the simulated GI system. By contrast, the cells were trapped within the Al capsules. Based on these data, effective encapsulation using alginate with CREP and PEG can enable JW15 to be released at a targeted anatomical site of activity within the GI system, thereby, enhancing the efficacy of probiotic cells. These protective effects can be leveraged during the development of probiotic products. PRACTICAL APPLICATION: Weissella cibaria JW15 (109 cells/mL) was encapsulated in biodegradable and biocompatible capsules, prepared by mixing 1.5% alginate with 1% chicory root extract powder (CREP) in 0.1 M CaCl2 and 0.05% PEG using an encapsulator. The optimal processing parameters were as follows: pressure, 100 mbar; vibration frequency, 350 Hz; voltage, 1.35 kV; and core flow rate, 2 mL/min. When the resulting capsules were subjected to a simulated gastrointestinal system for 6 hr, the cells were released into the small intestine, and up to 95% cell viability was preserved. These results suggest that capsules made from alginate with CREP and formulated using calcium and PEG are a promising delivery system for probiotic cells.