Seleção de bactérias láticas com potencial probiótico isoladas de frutas e avaliação da capacidade de sobrevivência de Limosilactobacillus fermentum em sucos de frutas

• Autor(a) principal: Rodrigues, Noádia Priscila Araújo
• Data de Publicação: 2021
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFPB
• Texto Completo: https://repositorio.ufpb.br/jspui/handle/123456789/21513
• topic: Alimentos funcionais; Lactobacillus spp; Testes de segurança; Propriedades tecnológicas; Análise multivariada; Functional foods; Safety tests; Technnologial properties; Multivariate analysis; CNPQ::CIENCIAS DA SAUDE::NUTRICAO

The development of functional fruit-based foods with probiotics is still a challenge for the industry, which demonstrates the need to obtain isolates with the hability to adapt to these matrices. The aim of this study was to select isolates of lactic acid bacteria (BAL) from banana, orange, apple and grape samples, through their probiotic and technological characteristics in vitro and survival in different food matrices and to verify the viability of two strains of Limosilactobacillus fermentum isolated from products of fruit processing in orange and apple juices during refrigerated storage and when exposed to simulated gastrointestinal digestion. Isolation, phenotypic characterization and pre-identification of isolates obtained from fruit samples were carried out, followed by safety tests and exclusion of unsafe samples. Subsequently, in vitro tests were carried out to assess the technological and probiotic potential of the remaining isolates. Through the use of multivariate statistical analyzes, the most promising isolates were selected, identified by sequencing the 16S-rRNA gene and evaluated for their ability to survive in different food matrices. Two strains of Limosilactobacillus fermentum isolated in previous studies of fruit processing by-products, previously characterized as presumably for use as probiotics in food, were incorporated into apple and orange juices and evaluated for their ability to survive during refrigerated storage and when subjected to the simulated digestion process. 93 BAL isolates were obtained from fruit samples, but 27 isolates were excluded in safety tests. Among the remaining 66 isolates, four were selected as the most promising and safe for use in food based on technological tests and probiotic potential for use in food, which were identified as Lactobacillus sp. or Levilactobacillus brevis. These isolates showed good survival capacity for 28 days of cold storage with viable counts> 6 log CFU / mL and percentage of metabolically active cells between 26 and 72%, at the end of the period, in fruit juices, vegetable puree, meat stew and UHT milk. The two isolates of L. fermentum with probiotic potential derived from frui byprodcts when inoculated in apple and orange juices showed good survival capacity, as indicated by high viable counts (>6 log CFU/mL during refrigeration and >4 log CFU/mL in TGI) and by physiologically active cell subpopulations (>30%), during 28 days of cold storage as well as when exposed to a simulated digestion in these substrates. The results of this study showed that fruits can be sources of LAB isolates with probiotic potential and that a protocol including isolation, phenotypic characterization, exclusion with safety tests and selection based on technological and physiological properties can be applied to obtain isolates with properties compatible for use as probiotics and with ability of survive in different food matrices, and also those isolated from fruit by-products when inoculated in fruit juices have potential for survival during refrigerated storage and during simulated digestion process.