Biomass production of autochthonous lactic acid bacteria in culture media with different types of cheese whey and optimization of drying processes

Abstract

There is a growing demand and popularity from consumers for functional foods, including those with beneficial microorganisms, which has challenged the industry to produce large quantities of viable cultures, keeping their functionality and being stable during processing and storage of these products. Lactic Acid Bacteria (LAB) have numerous applications in the food and pharmaceutical industry, notably the category of probiotic cultures, widely used for the production of dairy products, and also those cultures with technological characteristics such as bioconservation or autolytic activity. However, large-scale LAB production is not quite that simple, since they are fastidious microorganisms and production of biomass with concentrations of 1010 viable cells per gram or milliliter implies the use of appropriate culture media for each species. The choice of a culture medium for microorganism production is made considering the costs, cell production efficiency and ease of cell recovery. Cheese whey, the liquid resulting from precipitation and removal of milk during cheese making, accounts for 80 to 90% of the total milk volume used. Even being considered as a byproduct, it is a valuable source of nutrients and can be used as a substrate for LAB growth, but studies should be done to determine the necessary supplements and the ideal conditions for growth of these cultures. In addition, it is also important that LAB cultures are able to keep their functionality and viability during the drying processes, during storage and during the production of the product in which they will be applied. Thus, the objective of this project is to formulate culture media using cheese whey from the production of two traditional Brazilian cheeses (sweet whey from Minas fresh cheese and acid whey from processed cheese - requeijão) for commercial production of LAB cultures (one LAB strain with interesting technological and functional characteristics), besides evaluating the effectiveness of cheese whey as a protective agent of this strain during freeze-drying and spray-drying and during the storage period. This project is the starting point for the implementation of commercial production of LAB cultures at the TECNOLAT/ITAL, providing a new type of service to Brazilian dairy producers, since so far there is not yet a national company in Brazil that produces and distributes LAB and probiotic cultures. (AU)