Determination of viability of microencapsulated Saccharomyces boulardii yeast added to pomegranate vinegar

Considering lactose intolerance (65%), milk allergies and the increasing trend towards vegetarianism in the world population, interest in new non-dairy probiotic foods is increasing day by day. Saccharomyces boulardii is a probiotic yeast whose reliability has been proven by EFSA (Europen Food Safety Authority) and is used as a preventive and therapeutic agent in the treatment of gastrointestinal disorders such as microbial and antibiotic-induced diarrhea in children and adults. S. boulardii has the potential to be used in fruity, fermented and acidic foods due to its low pH and high resistance to organic acids. The encapsulation method is effective in protecting probiotics from stress conditions such as high acidity. In this thesis study, S. boulardii CNCM I-745 (Biocodex, France) probiotic yeast, in free cell (SH) form, was encapsulated in symbiotic microencapsulates with inulin prebiotic added alginate (ALG-INU) and bilayer alginate and chitosan (CTS-ALG-INU) polymers and added to pomegranate vinegar (3.6 pH). Some chemical properties (titratable acidity value, pH value, amount of water-soluble dry matter) and the number of S. boulardii yeasts of pomegranate vinegar samples were determined weekly during the 4 week storage period at 4±1°C. As a result of the study, the numbers of S. boulardii yeast initially added to pomegranate vinegar at the level of 8 log cfu/mL at the end of 4 weeks storage at 4±1°C for SH, ALG-INU and CTS-ALG-INU the living cell numbers were determined as 4.27, 7.24 and 5.02 log cfu/mL respectively. It has been understood that alginate polymer protects S. boulardii yeast in pomegranate vinegar environment much better than chitosan. It is thought that chitosan polymer interacts with acetic acid and has a negative effect on yeast. According to pH and titratable acidity values, it was concluded that S. boulardii yeast did not cause any fermentation in pomegranate vinegar. The results obtained from this study will shed light on future studies on the use of S. boulardii yeast in high-acidic fermented foods.