Fluidized Bed Microencapsulation of Lactobacillus Sporogenes with Some Selected Hydrocolloids for Probiotic Bread Production

This research investigated the encapsulated Lactobacillus Sporogenes resistance to simulated gastric acid condition and extreme heat treatment and the aim was the production of probiotic bread using the encapsulated probiotic. Microcapsules were produced using the L. Sporogenes by a two-step fluidized bed granulation and button spray coating technique with microcrystalline cellulose powder and alginate or xanthan gum as the first layer to enhance bacterial survival under gastrointestinal conditions and gellan or chitosan as the outer layer to increase heat resistance. The results indicated that encapsulation efficiency decreased with increasing the level of both alginate and xanthan and microcapsule containing 0.5% xanthan had significantly higher (p <0.05) encapsulation yield. In the case of acid resistance, 1.5% xanthan in the wall matrix made significantly (p <0.05) higher viability of the probiotics. 0.5% chitosan in the outer layer of the microcapsules caused probiotic more resistant to the heat treatment of 90°C for 15 min. Heat treatment for 30 min at 90°C decreased severely the probiotics population. Moreover, the results from SEM indicated that chitosan represented the smoother surface which is an essential factor to protect cells against environmental condition. Evaluation of encapsulated Probiotic viability in bread showed that 1.5% gellan in outer layer caused higher survivability 24 h after baking. These finding indicated that the application of alginate and chitosan in the microcapsules can protect the L. Sporogenes and considered as an effective method in probiotic bread production.