ABSTRACT
ABSTRACT In the last decade, thrombosis has been one of the pathologies with high incidence creating great concern in Health Institutes all around the world. Considering this, the aim of this research was to determine the antithrombotic activity of peptides released during lactic fermentation. Reconstituted skim milk powder was fermented by Lactobacillus casei Shirota and Lactobacillus johnsonii LA1 isolated from commercial fermented milks. The hydrolysis degree and proteolytic profile were analyzed by trinitrobenzenesulfonic acid spectrophotometry method and by peptide polyacrylamide electrophoresis gel separation. The milk fermented by Lactobacillus casei Shirota exhibited a higher concentration of free amino groups than that fermented by Lactobacillus johnsonii LA1. Additionally, in both fermentation systems peptides with molecular weights lower than 1.4 kDa were observed. The highest inhibition of thrombin (31.67±2.35%) was observed in milk fermented by Lactobacillus johnsonii LA1 at 10 hours of fermentation. Finally, no relationship was found between the antithrombotic capacity and the proteolytic profile.
ABSTRACT
Leites fermentados por Lactobacillus rhamnosus e Lactobacillus fermentum, isolados de queijos artesanais, foram produzidos e avaliados quanto às características físico-químicas e microbiológicas durante 45 dias de estocagem a 8-10ºC. Análises sensoriais foram realizadas aos 15 e 60 dias. Ambos os leites fermentados apresentaram contagens adequadas das bactérias láticas, superiores a 108 UFC/g, durante toda a estocagem. As médias das análises físico-químicas e microbiológicas dos produtos durante a estocagem foram iguais e todos atenderam às especificações da legislação brasileira. Melhores resultados de avaliações sensoriais (P<0.05) foram aos 15 dias de estocagem. Leites fermentados por L. fermentum obtiveram melhor aceitação sensorial aos 60 dias de estocagem, quando apresentavam acidez titulável inferior à encontrada no leite fermentado por L. rhamnosus. Portanto, a utilização dessas culturas pode ser viável para a elaboração de novos leites fermentados, que apresentariam prazo de validade de 45 dias de estocagem sob refrigeração.(AU)
Subject(s)
Milk , Food Storage/methods , Fermented Foods/analysis , LactobacillusABSTRACT
Existe una gran variedad de leches fermentadas con bacterias lácticas, con propiedades que promueven la salud. Recientemente se ha comunicado que las proteínas de los alimentos pueden, además, ejercer otras funciones in vivo, por medio de sus péptidos con actividad biológica. Estos péptidos se encuentran encriptados dentro de la estructura primaria de las proteínas y pueden ser liberados por fermentación de la leche, hidrólisis enzimática, o bien durante el tránsito gastrointestinal. Las funciones que presentan son diversas, ya que pueden actuar en diferentes sistemas del cuerpo humano: el cardiovascular, el digestivo, el endocrino, el inmune y el nervioso. Los péptidos bioactivos que presentan un efecto en el sistema cardiovascular (antihipertensivo, antitrombótico, antioxidante o hipocolesterolémico) pueden reducir los factores de riesgo para la manifestación de enfermedades crónicas y ayudar a mejorar la salud humana. Los péptidos bioactivos más estudiados son aquellos que ejercen un efecto antihipertensivo a través de la inhibición de la enzima convertidora de angiotensina (ACE). Este documento se enfoca en la producción de péptidos antihipertensivos inhibidores de la ACE en leches fermentadas, en su historia, y en las pruebas in vivo realizadas en ratas y en humanos, donde se ha demostrado su efecto hipotensor.
There is a great variety of fermented milks containing lactic acid bacteria that present health-promoting properties. Milk proteins are hydrolyzed by the proteolytic system of these microorganisms producing peptides which may also perform other functions in vivo. These peptides are encrypted within the primary structure of proteins and can be released through food processing, either by milk fermentation or enzymatic hydrolysis during gastrointestinal transit. They perform different activities, since they act in the cardiovascular, digestive, endocrine, immune and nervous systems. Bioactive peptides that have an antihypertensive, antithrombotic, antioxidant and hypocholesterolemic effect on the cardiovascular system can reduce the risk factors for chronic disease manifestation and help improve human health. Most studied bioactive peptides are those which exert an antihypertensive effect by inhibiting the angiotensin-converting enzyme (ACE). Recently, the study of these peptides has focused on the implementation of tests to prove that they have an effect on health. This paper focuses on the production of ACEinhibitory antihypertensive peptides from fermented milks, its history, production and in vivo tests on rats and humans, on which its hypotensive effect has been shown.
Subject(s)
Animals , Cattle , Humans , Rats , Cultured Milk Products , Hypertension/diet therapy , Angiotensin-Converting Enzyme Inhibitors/isolation & purification , Bifidobacterium/enzymology , Cultured Milk Products/enzymology , Cultured Milk Products/microbiology , Lactobacillus/enzymology , Lactococcus/enzymology , Milk Proteins/metabolism , Peptides/pharmacokinetics , Peptides/pharmacology , Streptococcus/enzymologyABSTRACT
The potential of in vitro probiotic Lactobacillus spp. was evaluated in fermented milks marketed in Belo Horizonte, MG, Brazil. Of the samples analyzed, 86.7% had at least 10(6) CFU/mL of Lactobacillus spp., complying with the Brazilian quality standards for fermented milks. Furthermore, 56.7% had minimum count ranging from 10(8) to 10(9) CFU/mL, which is in accordance with legal parameters. The remaining 43.3% would not be able to satisfactorily guarantee benefits to consumers. The amount of Lactobacillus spp. varied between batches of products, which may indicate failures in monitoring during manufacture, transport or storage. All strains of Lactobacillus spp. showed some inhibitory activity against the indicator microorganisms, being more pronounced against pathogenic microorganisms than against non-pathogenic (P<0.05). Samples of Lactobacillus spp. showed different profiles of antimicrobial susceptibility, with an occurrence of cases of multidrug resistance. All strains tested showed sensitivity to bile salts (0.3%) and resistance to gastric pH (2.0). Lactobacillus spp. of commercial fermented milks should be present in higher amounts in some brands, be resistant to bile salts and have no multiple resistance to antimicrobials.
O potencial probiótico in vitro de Lactobacillus spp. foi avaliado em leites fermentados comercializados em Belo Horizonte, MG, Brasil. Das amostras analisadas, 86,7% apresentaram quantidade mínima de 106UFC/mL de Lactobacillus spp., enquadrando-se no padrão brasileiro de qualidade de leites fermentados. Além disso, 56,7% apresentaram quantidade mínima de 108a 109UFC/mL, estando em conformidade com os parâmetros legais vigentes. As demais 43,3% não estariam aptas a garantir satisfatoriamente efeitos benéficos aos consumidores. Observou-se variação na quantidade de Lactobacillus spp. entre lotes dos produtos, o que pode indicar falhas no monitoramento durante a fabricação, transporte ou estocagem destes. Todas as amostras de Lactobacillus spp. demonstraram alguma atividade inibitória frente aos microrganismos indicadores, sendo mais intensa contra microrganismos patogênicos que não patogênicos (P<0,05). As amostras de Lactobacillus spp. apresentaram diferentes perfis de susceptibilidade aos antimicrobianos, ocorrendo casos de multirresistência. Todas as amostras testadas apresentaram sensibilidade in vitro a sais biliares (0,3%) e resistência in vitro ao pH gástrico (2,0). Lactobacillus spp. dos leites fermentados testados deveriam estar presentes em quantidades mais elevadas em algumas marcas comerciais, possuir resistência aos sais biliares e não apresentar resistência múltipla aos antimicrobianos.