In this study, Bacillus subtilis natto was encapsulated in alginate, either coated with or mixed with xanthan gum as a supplemental component. The encapsulated bacteria were then evaluated for their survival in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF). The results showed that B. subtilis natto biomass had a thrombolytic ability compared to the control sample. The viability of encapsulated B. subtilis natto was improved in which alginate 2.5% (w/v) had a high encapsulation efficiency, and there was no difference between the samples with or without the xanthan gum supplement. In the SGF and SIF tests, the viability of B. subtilis in samples supplemented with xanthan gum was higher than in samples that contained only alginate. Additionally, there was no significant difference in viability between the samples that mixed xanthan gum with alginate and those that were coated with it. The results indicated that adding xanthan gum is necessary to increase alginate's protective effect on B. subtilis natto.

Bread is a popular food in the world because of its variety and convenience. Currently, studies on the adding probiotics to bread are limited due to the adverse effects of processing, such as baking temperature, aerobic environment to the probiotic bacteria. The objective of this study was to produce probiotic cream bread, in which Lactobacillus acidophilus was microencapsulated with Alginate 2% (A); Alginate 2% + maltodextrin 1% (AM); Alginate 2% + xanthan gum 0.1% (AX); and Alginate 2% + maltodextrin 1% + xanthan gum 0.1% (AMX). Microcapsules were added to the kernel, conducting encapsulation yield investigations, survival in baking, preservation of bread, and in simulated gastric fluid and simulated intestinal fluid conditions after 8 days of storage. The results showed that the addition of xanthan gum enhanced the encapsulation yield, it reached 92.9% and 92.37% in AMX and AX samples, respectively. The viability of L. acidophilus during baking was decreased by 3.64 and 3.75 Log (CFU/bread) in AMX and AM samples, compared to A and AX which were decreased by 4.75 and 4.44 Log (CFU/ bread). In SGF (Simulated Gastric Fluid) and SIF (Simulated Intestinal Fluid) conditions, the AMX microcapsules provide the best probiotic protection among the four tested carriers. The combination of xanthan gum and maltodextrin in alginate matrix, eventually leading to having dual efficiency: First, xanthan gum would act as buffers that reduce acid activity; Second, maltodextrin acting as a protective agent of L. acidophilus against high temperature as well as potential prebiotic that improve the viability of probiotic.