Downstream process for the production of yeast extract using brewer's yeast cells

A downstream process was developed for the production of yeast extract from brewer's yeast cells. Various downstream processing conditions including clarification, debittering, and the Maillard reaction were considered in the development of the process. This simple and economic clarification process used flocculating agents, specifically calcium chloride (1%). After the clarification step, a Maillard reaction is initiated as a flavor-enhancing step. By investigating the effects of several operation parameters, including the type of sugar added, sugar dosage, glycine addition, and temperature, on the degree of browning (DB), glucose addition and reaction temperature were found to have significant effects on DB. A synthetic adsorption resin (HP20) was used for the debittering process, which induced a compositional change of the hydrophobic amino acids in the yeast hydrolysate, thereby reducing the bitter taste. The overall dry matter yield and protein yield for the entire process, including the downstream process proposed for the production of brewer's yeast extract were 50 and 50%, respectively.