Production and formulation of synbiotic dark chocolate based on Lactobacillus casei microcapsules and chestnut powder and evaluation of probiotic survival during storage

In various food industries, including chocolate, the use of fibers has been prevalent in recent years. Considering the known nutritional value of chestnut in this study, after fiber preparation, evaluation tests of phenolic compounds and accumulated tannins content were investigated. The positive effect of Microencapsulation on the tolerance of simulated gastric and intestinal conditions by probiotics has been proved. The results showed that the total phenolic compounds were 184.32, and the amount of accumulated tannins was 5.1 mg/g.  Also, microcapsules are spherical and homogeneous with between 100 and 300 μm. There was no agglomeration state between the particles, and it was uniform. The population of bacteria trapped in microcapsules was 7× 10 7 colonies per gram. Also, increasing the percentage of microcapsules and chestnut fiber increased the percentage of moisture, hardness, and acidity of chocolate treatments. The Lactobacillus casei survival rate was at treatment T3 in the highest possible condition among the research treatments. During storage, the microbial population index decreased. In terms of sensory properties, treatment T6 had less desirability than other treatments.