UPGRADING THE NUTRITIONAL VALUE OF GRAPE POMACE BY USING SACCHAROMYCES CEREVISIAE IN SOLID STATE FERMENTATION

Solid-state fermentation is a technique that utilizes a solid material as a support for the growth of microorganisms in the absence or near absence of water. It has some advantages compared to submerged fermentation like lower cost, easier product recovery and lower energy requirements for agitation. In addition, it allows the use of agro industrial wastes, which in recent years have been generated in larger quantity due to the increasing activities of the industries. This work was carried out to optimize the growth of the yeast Saccharomyces cerevisiae 203 in grape pomace of Malbec grape from the Vinícola Franco Italiana. To establish the cultivation conditions as the initial moisture content and the concentration of sugarcane molasses added to the substrate were tested After that, growth kinetics experiments were performed in flask and tray bioreactor with. 60% of initial moisture content, supplementation with molasses concentration of 0.75 mL/g of grape pomace, initial pH of 5.0 and temperature of 28 °C. The samples were collected in 0h, 24h, 48h, 72h and 96h for analysis of growth, sugars, proteins and pH. The results showed a good growth during the first 48h of each culture, and tray bioreactor cultivation (5.25 x 108 CFU / g) outlined a more pronounced growth curve compared to flasks cultivation (4.9 x 108 UFC / g). Peak growth coincided with sugars decreasing curve, agreeing to a higher consumption of this nutrient to supply the cells needs. The curve representing the amount of proteins in the medium also increased during both types of cultivation and it is related to microbial growth.