Еffect of downstream processing on content of glutathione and cell viability during production of inactive dry yeast

Glutathione (GSH) is a tripeptide thiol with important protective activity in living organisms. Due to its ability to prevent oxidation, this substance is commonly used in biotechnological products. The fed-batch process with yeasts of the genus Saccharomyces coupled with downstream processing to obtain inactive dry yeasts with high GSH content is the common method for industrial production. Short-term high-temperature treatment (1 minute at 105 °C) emerged as potentially optimal, achieving CFU/g is less than 102 while maintaining relatively high GSH levels. Another approach showed the promise of adjusting pH changes to levels of 2.4–3.0 without altering inactivation conditions (95 °C/30 min) as an alternative to the previous one. Further studies are needed to explore the complex interplay between acidic conditions, duration of inactivation, and temperature para- meters for simultaneously maximizing glutathione retention while controlling microbial viability.