Production and stabilization of new starter yeasts isolated from Brazilian artisanal cheeses

Abstract

Brazilian artisanal cheeses, besides their unique organoleptic characteristics, are one of the greatest representations of the national cultural identity. The sensory profile development of these products is mostly attributed to the yeasts that participate in different steps, from formulation to cure. Although traditional production practices favor the maintenance of the artisanal cheese's identity, some of these processes have been replaced by new technologies more appropriate to contemporary reality, such as controlled inoculation with purified dehydrated yeasts. On the one hand, these new practices guarantee the safety and the quality control of the products. On the other hand, the use of dehydrated yeasts allows the reduction of formulation and maturation time. The conservation of yeasts in dehydrated form has several advantages, such as long-term stability, easy application and handling. However, the water removal could be lethal for cells and may lead to decreased cell activity potential. Depending on the culture conditions the yeasts produce certain substances, e.g. glutathione and trehalose, which naturally protect them from subsequent stress, i.e., dehydration. Thus, multiple aspects of the stabilization of yeasts isolated from artisanal Brazilian cheeses still remain to be defined as: (i) determination of the yeasts cultivation and dehydration conditions; (ii) evaluation of microbial activity after dehydration-rehydration; (iii) formulation and validation of cheeses produced with dehydrated yeasts. The execution of this project will allow to outline new conservation strategies for starter yeasts isolated from Brazilian artisanal cheeses. Besides contributing to add value to artisanal products, this project is mainly of great interest for Brazilian society, Science and Economy. (AU)