Wild yeasts isolated from fruits have biotechnological potential in fermentation processes,
due to their ability to ferment complex sugars, tolerate both high temperatures and freezing,
high concentrations of ethanol and media with high osmotic pressure. Unicellular Protein
(SCP) are proteins derived from dry cells of microorganisms. Fermentation is one of the main
microorganisms used for fermentation processes and production of SCP due to the
Presumption of Qualified Safety certificate of several species. In this study, wild yeasts
isolated from Amazonian fruits were evaluated for their application in bread fermentation and
SCP production. Toxicity tests (biogenic amines and hydrogen sulfide), bread fermentation
screening (stress test, carbohydrate fermentation, growth at different temperatures,
osmotolerance, cryotolerance and ethanol tolerance) and SCP production (optical density,
sugars ). total reducers, growth kinetics and protein analysis), resulting in the selection of two
yeasts for the fermentation of breads (BCL 49.1 and BCL 5.2), and one (BCL 188.4) was
chosen for the production of SCP, due to the higher production of proteins in the substrate
used (40.22% without pineapple crown flour medium and 81.71% without YEPG broth).
Breads made with BCL 49.1 and BCL 5.2 yeasts had less facilities than commercial S.
cerevisiae, however, when it comes to the aroma profile of BCL 5.2, there was no significant
difference compared to the control yeast. The addition of SCP to breads improved changes in
physicochemical characteristics, such as an increase in lipid, ash, fiber and carbohydrate
contents, and excess total reducing sugar contents. There was no statistical difference in
protein content between enriched and non-enriched breads. It was concluded that the wild
yeasts were able to ferment the breads and produce SCP with a high protein content, however,
due to the amount of SCP used, they did not directly affect the amount of proteins in the
breads, but the physicochemical characteristics.
|
