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Dietary supplementation with lactic acid bacteria to maintain or improve intestinal health is advocated. Weissella spp. are present in different fermented vegetable‐based foods like kimchi, as well as in the normal gastrointestinal (GI) tract of humans. Weissella cibaria strains have been proposed as potential probiotics. Freeze‐drying is a promising treatment method for these strains for industrial applications and to increase the accessibility of their health‐promoting benefits. Moreover, probiotic strains need to be able to survive in the host GI tract, and acid and bile are both environmental stressors that can reduce strain survival. Therefore, this study evaluated the effect of the combination of protective agents on the acid and bile resistance of W. cibariaJW15 after freeze‐drying. A protective agent combination with a 1:1 ratio of 5 g + 5 g/100 ml w/v soy flour + yeast extract (SFY) retained nearly 100% viability after freeze‐drying and was resistant to artificial bile acids. Remarkably, skim milk + soy flour (SSF) was resistant to an acidic solution, and the viability of W. cibariaJW15 in artificial gastric acid was enhanced when treated with this mixture. Furthermore, SFY and SSF were found to maintain high numbers of viable cells with a low specific rate of cell death (k) after storage at 50°C, 60°C, and 70°C. These results support an effective probiotic formulation system with a high number of viable cells, and its protective effects can be leveraged in the development of probiotic products with health benefits. The addition of soy flour and yeast extract powder (SFY, 5 g + 5 g/100 ml w/v) as a protective agent during the freeze‐drying process can maintain the viability of Weissella cibaria, ensuring the proper administration of probiotics to their destinations. Furthermore, SFY was evaluated for its effects on storage stability of the freeze‐dried powder through an accelerated storage test. We found that this protective agent is an effective method for protecting the health benefit of probiotic products and is desirable for industrial development. [ABSTRACT FROM AUTHOR]

Freeze-drying is a well-known dehydration method widely used to preserve microorganisms. In order to produce freeze-dried yeast starter culture for the brewing purpose of African sorghum beer, we tested protective agents (sucrose, glucose, glycerol) in combination with support materials (millet, maize, sorghum, and cassava flours) at 1:1 ratio (v/v). The yeast strains Saccharomyces cerevisiae F12-7 and Candida tropicalis C0-7 previously isolated from sorghum beer were used in a mixed culture at a ratio of 2:1 ( C. tropicalis/ S. cerevisiae). After the freeze-drying, the residual water contents were between 0.78 -2.27%, 0.55 -4.09%, and 0.40-2.61%, respectively, with sucrose, glucose and glycerol. The dried yeasts viabilities were between 4.0% and 10.6%. Among the protective agents used, sucrose was found to be the best protectant giving cell viabilities of 8.4-10.6%. Considering the support materials, millet flour was the best support after drying. When the freeze-dried yeast powders were stored at 4°C and room temperature (25-28°C) for up to 3 months, the survival rates were the highest with cassava flour as the support material. [ABSTRACT FROM AUTHOR]