Evaluation of survival of encapsulate d Lactobacillus casei with sodium alginate and silica

Microencapsulation is one of the most effective methods for increasing the viability of probiotic bacteria. In this study, the use of alginate-silica coating for the purpose of encapsulation of Lactobacillus casei was evaluated. For this purpose, the encapsulation process was carried out with sodium alginate 1.5% and different levels of silica (5, 10 and 15% v / v) by extrusion method. The survival of free and encapsulated bacteria at 4°C for 28 days was investigated. Chemical reaction andlinkage between alginate gel and silica were confirmed by FT-IR spectroscopy. With the addition of silica, the size of the capsules increased, but did not affect the encapsulation efficiency (p<0.05). The results showed that the number of free cells was reduced by 3.32 logarithmic cycles after the end ofthe storage period, while the decrease for the encapsulated bacteria was less significant. There was no significant difference between alginate and alginate samples with 5% silica in viability of 14 days.By increasing the concentration of silica, the number of live bacteria decreased during storage.