The Effect of Extrusion Voltage and Flowrate to the Viability and Survivability of Probiotic <em>L. casei</em> Encapsulated in Alginate-Chitosan

Abstract

Chitosan-coated L. casei containing alginate capsules (shortened as L. casei capsules) were prepared by extruding L. casei containing alginate solution at different extrusion voltage and and flow rate followed by coating the wet capsules in chitosan solution. This study aimed to determine the effect of extrusion voltage and sodium alginate liquid flow rate on the viability of L. casei bacteria in the encapsulation process. The encapsulation process in this study was carried out by the extrusion method using sodium alginate of 1% (w/v) and chitosan of 0.2% (w/v). The resulted beads were immersed in a simulated gastric fluid (SGF) (NaCl 0.2%; HCl 0.5 M with a pH of 1.5) for 1, 60, and 120 min at 37 °C. The number of L. casei cells before encapsulation was 12.3 log CFU. After encapsulation, the maximum viability of L. Casei obtained by voltage variations of 0 kV and flow rate 5 mL/min were 12.26 log CFU. After testing the beads in SGF for 1 min, the results obtained indicate that viability of L.casei in the sodium alginate - chitosan beads with an extrusion voltage of 0 kV and 5 mL/min was 11.8 log CFU/g. The result indicated that encapsulated L. casei in the sodium alginate - chitosan beads with a voltage of 0 kV and 5 mL/min was the highest survivability level of 97.38 %. The conclusions of the study were The higher extrusion voltage can kill more L. casei while the higher extrusion flow rate can protect more L. casei.