Identification of microorganisms present in sugar cane and pineapple juice sourdough prepared by fermentation and by the innoculation of lyophilized starter

• Autor(a) principal: Santos, Alvaro Cesar Krieck dos
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Cruzeiro do Sul
• Texto Completo: https://repositorio.cruzeirodosul.edu.br/handle/123456789/2290
• topic: CNPQ::CIENCIAS BIOLOGICAS::BIOLOGIA GERAL; Biotechnology; Enzymes; Fermentation; Yeast

Natural fermentation food products, such as bread, has gained notoriety in recent years for their organoleptic properties. The fermentation process is important for the modifications on the texture and flavor of the final product. The sourdough, a wild culture of bacteria and yeast has been used in bread making mainly because of the final flavor fermentative culture process provides to bread and baking products. The problem of natural fermentative culture poses lies on the fact that it is rarely available in the market, therefore, resulting difficult bakers to have access to it unless they start their own starter culture. A process which requires from 5 to 7 days. Sourdough bread and baking goods present a unique set of aromas, flavors and texture not found in products resulting from the use of Saccharomyces cerevisiae. The aim of this study was to identify microorganisms present in sugar cane and pineapple juices sourdough before and after the lyophilization process. Other the other hand of fresh sourdough, a lyophilized version of presents a longer shelf life and easier maintenance. For that, sourdough was obtained from starter cultures using sugar cane juice and the pineapple juice as carbon and microorganism source. Sugar cane presents several uses in our industry and presents a high amount of sucrose and pineapple juice has been used as the liquid for starter cultures and sourdough presenting interesting results in final baking products. The microorganisms present in those samples were isolated and identified in Petri dishes in deMan Rogosa Sharpe (MRS) and the Yeast extract Peptone Dextrose (YPD) medium to identify the presence of lactic acid bacteria and yeasts. Once identified, a molecular test was performed to identify more accurately microorganisms and yeasts present in both samples. In the sequence, 10% of sucrose was added to the samples before they were lyophilized to prevent cell damage during the process (cryoprotectant). Once lyophilized, they were inoculated in flour and water to create a new sourdough sample. Then, they were isolated in Petri dishes in MRS and YPD medium and analyzed and compared with the original samples. In the sequence, a molecular analysis was carried out, and, amongst other bacteria, Lactobacillus were found in greater number in sugar cane samples before and after lyophilization, being 69.9% and 80.06%. In pineapple samples were found most Pedicoccus, which are lactic acid bacteria, 83.40% and 76.90% before and after lyophylization, respectively. The eukaryote analysis presented 19.20% of Pichia kudriavzevii in in the sugar cane sample after lyophilization.