Bactérias láticas isoladas de subprodutos do processamento de frutas: avaliação do potencial probiótico e viabilidade tecnológicas em sucos de frutas

• Ano de defesa: 2017
• Autor(a) principal: Garcia, Estefânia Fernandes
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal da Paraíba; Brasil; Engenharia de Alimentos; Programa de Pós-Graduação em Ciência e Tecnologia de Alimentos; UFPB
• Palavras-chave em Português: Lactobacillus spp; Liofilização; Sucos; Controle de qualidade; Lyophilization; Juice; Quality control; CNPQ::CIENCIAS AGRARIAS::CIENCIA E TECNOLOGIA DE ALIMENTOS
• Link de acesso: https://repositorio.ufpb.br/jspui/handle/123456789/12730

Studies focusing on the potential of different species of acid-lactic bacteria (LAB) isolated from vegetables matrices has intensified in recent years. The aim of this research was to isolate and identify LAB from the by-products of fruit pulp processing and to analyze the probiotic and technological potential in fruit juices. The research was subdivided into three stages: initially, by-products were collected from the processing of pineapple, mango, acerola, cashew, soursoup, strawberry and guava for isolation of LAB strains. Isolated strains were identified for genus and/or species; Lactobacillus species were submitted to probiotic potential evaluation tests. Five strains of each species were then lyophilized and evaluated for maintenance of viability during storage under freezing when placed in commercial juices (grapes, apple and orange) and when exposed gastrointestinal tract (GIT) simulated conditions in juices. Also, the impact of the incorporation of the lyophilized strains on the physicalchemical and microbiological quality aspects of the juices was analyzed. Strains belonging to the genus Leuconostoc, Pediococcus, Lactococcus and, mainly, Lactobacillus were identified. Among the lactobacilli, the identification performed using the MALDI-TOF and 16S rRNA techniques showed efficacy of 86% and 100%, respectively. The identified species of lactobacilli were L. fermentum, L. plantarum, L. pentosus, L. casei, L. paracasei, L. nagelii and L. brevis. Regarding the evaluation of the probiotic potential, the tested cultures showed a reduction in pH = 3, but viability was not affected when exposed to pH 5 and 7.2; as well as in different concentrations of bile salts (1, 2 and 3%). The strains also exhibited inhibitory activity against pathogenic bacteria, and a variable profile of antibiotic resistance. The cultures showed similar growth pattern when cultivated in Man, Rogosa & Sharpe (MRS) broth and in general edible culture medium (GEM). The lyophilized cultures showed similar viability up to 30 days of freezing. After 120 days of storage, only L. pentosus 129 showed a count of <2 log CFU/mL, while the other strains had counts = 4 log CFU/mL. When added to juices, the cultures showed a count > 4 log CFU/mL even after 21 days of storage under refrigeration. The physical-chemical parameters (pH, acidity, total soluble solids, color and viscosity) studied did not vary until 14 days of storage. The capacity to tolerate GIT simulated conditions varied among the observed strains, having L. fermentum 111 and L. pentosus 129 been identified as the most sensitive to the exposure. The apple juice showed the greatest protective effect against GIT simulated conditions. Based on the results obtained, it was possible to verify that strains of different species of lactobacilli isolated from probiotic potential food processing byproducts, as well as the ability to maintain viability after lyophilization and incorporation into commercial fruit juices.