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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
421

Market and product assessment of probiotics and prebiotics and probiotic strains for commercial use

Brink, Marelize 03 1900 (has links)
Thesis (MSc Nutrition Science)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: Probiotics (live microbes) and prebiotics (non-digestible food-ingredients) are rapidly gaining interest worldwide as supplements and functional food ingredients but little South African information in this regard is available. Furthermore, the availability of South African produced probiotic concentrates for commercial use is also very limited. The aims of this study therefore were to complete a market and product assessment of probiotic and prebiotic containing products in South Africa and to evaluate probiotic strains for commercial use in South Africa. For the purposes of market and product assessment probiotic and/or prebiotic containing products manufactured in South Africa were identified. The scientific and legal correctness of health and content claims made on the labels of the products were assessed. An exploratory survey was conducted to determine the awareness of South African consumers of probiotics and prebiotics. For the evaluation of probiotic strains for potential commercial use in South Africa, a panel of twelve lactic acid bacteria (LAB) were screened for inhibitory activity against two porcine pathogens and indicator strains from the LMG-panel isolated from the faeces of patients diagnosed with AIDS. The five LAB with the best inhibitory activity were tested for growth in soymilk-base and for the effect of lyophilization on the inhibitory activity thereof. The effect of prebiotics on the growth and inhibitory activity of the strains was tested in vitro. A range of products containing probiotics and prebiotics available on the South African market was identified. Irregulatories concerning health claims on the labels were found, but content claims seemed to be less of a problem. The results also indicate that the proposed South African regulations for the labelling of probiotic and prebiotic containing products need to be revised to include the probiotic and prebiotic related health claims for which sufficient scientific evidence is available. The probiotic strains with potential for commercial use in South Africa that were identified, include Lactobacillus plantarum 423, Lactobacillus casei LHS, Lactobacillus salivarius 241, Lactobacillus curvatus DF38 and Pediococcus pentosaceus 34. These strains were grown successfully in soymilkbase and lyophilization did not have a negative effective on the inhibitory activity thereof. The growth and inhibitory activity of the five LAB were promoted when combined with 1% (w/v) Raftilose® Synergyl . It is concluded that although a variety of probiotic and prebiotic containing products are available on the South African market, the scientific and legislative correctness of especially health related claims is not satisfactory and that South African consumer awareness of these products is low. It is also concluded that a combination of at least three of the five identified LAB and 1% Raftilose® Synergy can be used by South African manufacturers for the production of probiotic and prebiotic containing supplements. / AFRIKAANSE OPSOMMING: Die belangstelling in probiotika (lewendige mikrobe) en prebiotika (onverteerbare voedselbestanddele) as supplemente en funksionele voedselbestanddele is besig om wêreldwyd toe te neem, alhoewel weinig Suid-Arikaanse inligting in hierdie verband beskikbaar is. Die beskikbaarheid van Suid-Afrikaans geproduseerde probiotika konsentrate vir kommersïele gebruik is ook baie beperk. Die doelwitte van hierdie studie was dus om 'n mark- en produkevaluering van probiotika- en prebiotika-bevattende produkte in Suid-Afrika uit te voer en om probiotiese stamme te evalueer vir uiteindelike kommersiële gebruik in Suid-Afrika. Vir die doel van die mark- en produkevaluering is probiotika- en prebiotika-bevattende produkte wat in Suid-Afrika vervaardig word geïdentifiseer. Die wetenskaplike en wetlike korrektheid van die gesondheids- en inhoudsaansprake op die etikette van die produkte is evalueer. 'n Markopname is uitgevoer om die bewustheid van Suid-Afrikaanse verbruikers van probiotika en prebiotika vas te stel. Vir die evaluering van probiotiese stamme vir potensïele kommersiële gebruik in Suid-Afrika is 'n paneel van twaalf melksuurbakteriëe getoets vir inhibitoriese aktiwiteit teen twee patogene geïsoleer uit varke asook teen indikator stamme van die LMG-paneel. Die vyf melksuurbakteriëe met die beste inhibitoriese aktiwiteit is getoets vir groei in sojamelk-basis en ook vir die effek van vriesdroging op die groei en inhibitoriese aktiwiteit van die stamme daarvan. Die effek van prebiotika op die groei en inhibitoriese aktiwiteit van die stamme is in vitro getoets. 'n Reeks van probiotika- en prebiotika-bevattende produkte wat beskikbaar is op die Suid-Afrikaanse mark, is geidentifiseer. Ongeruimdhede met die gesondheidsaansprake op die etikette is gevind, maar inhoudsaansprake was minder problematies. Die resultate dui ook daarop dat die voorgestelde Suid- Afrikaanse regulasies vir die etikettering van probiotika- en prebiotika-bevattende produkte hersien moet word om al die probiotika- en prebiotika-verwante gesondheidsaansprake waarvoor voldoende wetenskaplike bewyse beskikbaar is in te sluit. Die probiotiese stamme met potensiaal vir kommersiële gebruik in Suid-Afrika sluit die volgende in: Lactobacillus plantarum 423, Lactobacillus casei LHS, Lactobacillus salivarius 241, Lactobacillus curvatus DF 38 en Pediococcus pentosaceus 34. Hierdie stamme is suksesvol gekweek in sojamelk-basis en vriesdroging het nie' n negatiewe effek op die groei en inhibitoriese aktiwiteit daarvan gehad me. Die kombinasie van die vyf melksuurbakteriëe met 1% Raftilose® Synergy het die groei en inhibitoriese aktiwiteit daarvan bevorder. Die gevolgtrekking wat gemaak word is dat alhoewel 'n varrasie van probiotika- en prebiotikabevattende produkte beskikbaar is op die Suid-Afrikaanse mark, die wetenskaplike en wetlike korrektheid van spesifiek die gesondheids-verwante aansprake op die etikette daarvan nie bevredigend is nie en dat die bewustheid van die Suid-Afrikaanse verbruikers van hierdie produkte laag is. Die gevolgtrekking kan ook gemaak word dat 'n kombinasie van ten minste drie van die vyf geïdentifiseerde melksuurbakteriëe en 1% Raftilose® Synergy deur Suid-Afrikaanse vervaardigers gebruik kan word vir die vervaardiging van produkte wat probiotika en prebiotika bevat.
422

Influência do probiótico Lactobacillus acidophilus e prebióticos na redução e bioacessibilidade de aflatoxinas M1 e B1 em leite integral / Influence of probiotic Lactobacillus acidophilus and prebiotics in the reduction and bioacessibility of aflatoxins M1 and B1 in milk integral

Wochner, Katia Francine 30 March 2017 (has links)
O leite é uma das principais fontes de nutrientes essenciais ao crescimento, desenvolvimento e manutenção da saúde humana. No entanto, pode também ser um veículo de agentes tóxicos, causando sérios riscos à saúde em indivíduos que o consomem, em especial as crianças. Dentre os contaminantes de alimentos, as aflatoxinas se destacam, as quais são metabólitos secundários fúngicos relevantes na saúde humana e animal. Entre os análogos de aflatoxinas identificados até o momento, a aflatoxina B1 (AFB1) é a mais prevalente e a mais tóxica; quando ingerida por animais esta sofre biotransformação hepática convertendo-se parcialmente em aflatoxina M1 (AFM1), que é excretada no leite. Entretanto, estudos recentes tem demonstrado a presença de AFB1 em leite, discordando da literatura quanto à completa conversão desta em AFM1. Uma vez presente no leite, estas aflatoxinas podem resistir a maioria dos tratamentos para obtenção de derivados lácteos; portanto, podem estar presentes nos queijos e iogurtes. Neste trabalho, o objetivo foi avaliar a capacidade do Lactobacillus acidophilus isolado e em conjunto com prebióticos (inulina, oligofrutose, β-glucana e polidextrose) em reduzir a concentração de AFB1 e AFM1 e o efeito sobre a bioacessibilidade após digestibilidade em um modelo de digestão in vitro em leite contaminado artificialmente. Para tal, foi aplicado um delineamento experimental do tipo PlackettBurman para a avaliação do efeito de seis variáveis do processo (concentração de aflatoxina, tempo de incubação e concentração dos quatro prebióticos), um controle negativo (leite integral puro) e um controle positivo (leite integral fortificado com aflatoxina). Todos os ensaios com a adição do probiótico e prebióticos promoveram redução da AFB1 e AFM1 em leite, bem como da sua bioacessibilidade. Os níveis de redução variaram de 13,53 e 35,53% para AFB1 e 17,61 e 71,52% para AFM1. Quando comparada com o controle positivo a bioacessibilidade para AFB1 variou de 23,68 a 72,67% e 0% para AFM1 (100% de redução de bioacessibilidade). Para verificar a interação do probiótico e prebióticos com as aflatoxinas e possível modificação na estrutura proteica do leite, foi realizada espectroscopia na região do infravermelho por transformada de fourier (FTIR). Foi detectada alteração da região amida I (1700-1600cm-1) nos tratamentos adicionados do probiótico e prebióticos em relação ao tratamento contendo somente as aflatoxinas e leite, o que sugere a ocorrência de um deslocamento das aflatoxinas que estão ligadas a fração proteica do leite para a parede celular do probiótico. / Milk is a major source of essential nutrients for the growth, development and maintenance of human health. However, it can also be a vehicle for toxic agents, causing serious health risks in individuals who consume it, especially children. Among the food contaminants, aflatoxins stand out, which are important secondary fungal metabolites in human and animal health. Among aflatoxin analogues identified to date, aflatoxin B1 (AFB1) is the most prevalent and most toxic. When ingested by animals it undergoes hepatic biotransformation partially converting to aflatoxin M1(AFM1), which is excreted in the milk. However recent studies have demonstrated the presence of AFB1 in milk, disagreeing in the literature about the complete conversion of AFB1 to AFM1. Once present in milk, these aflatoxins can withstand most treatments to obtain dairy products; Therefore, may be present in cheeses and yogurts. The objective of this study was to evaluate the ability of Lactobacillus acidophilus alone and in conjunction with prebiotics (inulin, oligofrutose, β-glucan and polydextrose) to reduce the concentration of AFB1 and AFM1 and the effect on bioavailability after digestibility in a digestion model In vitro in artificially contaminated milk. For this, a Plackett-Burman experimental design was used to evaluate the effect of six process variables (aflatoxin concentration, incubation time and concentration of the four prebiotics),a negative control (pure whole milk) and a positive control (Whole milk fortified with aflatoxin). All probiotic and prebiotic assays promoted reduction of AFB1 and AFM1 in milk as well as its bioavailability. Reduction levels ranged from 13.53 and 35.53% for AFB1 and 17.61 and 71.52% for AFM1. When compared to the positive control the bioaccessibility for AFB1 ranged from 23.68 to 72.67% and 0% for AFM1 (100% reduction in bioaccessibility). To verify the interaction of probiotic and prebiotics with aflatoxins and possible modification in the protein structure of the milk, spectroscopy was performed in the infrared region by fourier transform (FTIR). It was detected alteration of the amide I region (1700-1600cm-1) in the probiotic and prebiotic treatments in relation to the treatment containing only aflatoxin and milk, suggesting the occurrence of aflatoxin displacement that is linked to the milk protein fraction to the cell wall of the probiotic.
423

Historie kojenecké výživy od roku 1945 do roku 2008 / History of infant nutrition since 1945 to 2008

VACUŠKOVÁ, Miluše January 2009 (has links)
Nutrition of children of each age has its particular aspects. For the new born and infantile age it is mainly breast-feeding that is very significant. Nutrition with breast milk is ideally balanced, ensures the intake of high-quality nutrition that is well tolerated by the young organism and ensures the optimal growth and psychological development of the child. Thanks to its composition, breast milk increases the protective impact on the child with respect to infections and creates a natural bond between the mother and the child. In the Thesis, I was trying to look up decisive moments in the infantile nutrition concept both in this country and worldwide and to map the issue of breast feeding and formula feeding since the end of the Second World War up to the present. Also, I wanted to emphasize the irreplaceability of breast milk as wel as supplementing of artificial milks with probiotics, prebiotics, synbiotics and their importance in the nutrition of children. Objective No. 1 of the Thesis has been to look up the key points in the infantile nutrition concept in the world since the beginning of the nineteenth century and since 1945 until this day in the Czech Republic. Objective No. 2 has been to prove that infantile formula nutrition has been focusing also on the immunological aspect apart from the nutritional ones. Objective No. 3 has been to create and aducational program proposal, which can serve as a practical guide for the application of theoretical data in clinical practice. Data necessary to achieve the determined objectives have been acquired by studing, analyses and comparison of available written documents relating to the natural and formula nutrition of infants. Most of these documents have been intended for the educational purposes at secondary school and universities in the Czech Republic. Also, data heve been taken from publications for parents and broad public published since 1945 until this day. By way of illustration, certain charts containing schemes of artificial nutrition corresponding to the time of creation have been used. On these schemes I wanted to show the chages in the concepts brought about by the development not only in the knowledge and thinking of people dealing with the nutrition of infants but also in the new possibilities and technology of the food processing industry.
424

Vliv vybraných krmných doplňků na výskyt kokcidií v zažívacím traktu slepic / Influence of selected feeding supplements on the occurrence of coccidias in digestive tract of chickens

PAZDERKOVÁ, Lenka January 2015 (has links)
Taking preventive measures has a major impact on the overall health status of poultry in every breeding and it can prevent considerable economic losses in this way. The aim of this study was to obtain basic knowledge about the occurence of coccidia oocysts in the faeces and the occurrence of pathological changes in the intestinal mucosa of broiler chickens after the use of selected feed supplements. Experiment was made during winter 2013 and summer 2014 with 250 specimens of one-day broiler chickens. Four experimental groups (prebiotics, probiotics, homeopathy, coccidiostats) and one control group were created. Treated groups were administered by Selected feed supplements were served to chickens during 14 days since the sixth day of their life. Mixed faeces samples were collected twice a week and processed in the laboratory. Also the frequency of coccidia oocysts was monitored under the light microscope. Intestines were collected during the slaughters of chickens (five pieces from every group) and tested to confirm or disprove pathological changes associated with coccidiosis of poultry. Intestines were collected three times after seven days. The Reduced frequency of occurrence of coccidia oocysts in faeces of chickens in all groups of the winter and the summer trial period was demonstrated, while pathological changes of the intestinal mucosa were not proved.
425

Avaliação das atividades antimicrobiana, antioxidante e capacidade de bioacumulação de selênio em células de Enterococcus

Pieniz, Simone January 2010 (has links)
As bactérias ácido lácticas (BAL) possuem papel importante em uma ampla variedade de alimentos, incluindo produtos lácteos e cárneos. Neste trabalho foram investigadas as atividades antimicrobiana e antioxidante, do sobrenadante bruto e do extrato intracelular, de 36 BAL isoladas de produtos lácteos e cárneos. Estas bactérias foram identificadas através do seqüenciamento do rRNA da região 16S. A análise através do GenBank BLAST revelou que todos os isolados pertencem ao gênero Enterococcus. Três isolados foram identificados como E. hirae, um isolado como Enterococcus sp., 17 como E. faecium e 15 como E. faecalis. A atividade antimicrobiana frente ao microrganismo indicador Listeria monocytogenes foi observado em 21 isolados, utilizando o sobrenadante bruto, destacando-se com os maiores halos de inibição os isolados IS 196 (10,7 mm) e IS 197 (11,0 mm) e, em 7 isolados, utilizando o extrato intracelular, os maiores halos de inibição foram obtidos com os isolados IS 196 (9,7 mm) e IS 197 (9,3 mm), sendo estes dois isolados identificados como E. faecium. A avaliação da atividade antioxidante foi realizada por três métodos distintos. Os 36 isolados apresentaram atividade antioxidante pela determinação às Substâncias Reativas ao Ácido Tiobarbiturico (TBARS), utilizando tanto o sobrenadante bruto quanto o extrato intracelular. A A capacidade antioxidante também foi verificada pelo seqüestro de radicais livres através do método de ABTS (2,2 azino-bis (3-•+etilbenzotiazolino-6-ácido sulfônico)) e pela captura do radical DPPH (2,2-difenil-1-picrilhidrazil). Nestes dois métodos verificou-se que apenas as amostras do sobrenadante bruto demonstraram capacidade antioxidante. A atividade antioxidante mais elevada foi observada nos isolados IS 196 e IS 197. Foi realizado também o enriquecimento das espécies de Enterococcus com selênio (Selenito de Sódio - Se(IV)). Neste estudo, selecionaram-se os isolados que bioacumularam maior concentração de Se(IV) na biomassa, BAL 14 e BAL 18, identificados como E. faecalis e E. faecium, respectivamente. Os isolados tiveram ótimo crescimento à 35ºC por 24 h (DO BAL 14=1,4 e BAL 18=1,5), a remoção 600ótima do selênio foi verificada com o pH inicial de 7,0 e temperatura de 25ºC. Através da curva de crescimento observou-se que após 8 h de incubação, as culturas BAL 14 e BAL 18 apresentaram a maior produção de biomassa (DO=1,42 e 1,41) e bioremoção do Se(IV) (14,89 e 14,79 mg L), 600-1respectivamente. Quantidade considerável de selênio foi detectada na biomassa de E. faecium (0,4599 mg g de peso seco e E. faecalis (0,4759 mg g de peso -1-1seco). Estes resultados mostram que estas bactérias podem auxiliar particularmente na redução ou inibição de microrganismos patogênicos, na inibição da oxidação de alimentos e ração animal, bem como reduzir os danos oxidativos provocados pela produção de radicais livres nos organismos vivos. A absorção significativa de Se(IV) pelas espécies de Enterococcus observados neste estudo, indicam que estes microrganismos podem ser utilizados para estudos posteriores visando à suplementação alimentar animal, através da utilização da biomassa produzida pelos Enterococcus enriquecidos com Se(IV). / The lactic acid bacteria (LAB) have an important role in a wide variety of foods, including dairy products, meat and fermented foods. In this study, antimicrobial and antioxidant activities of culture supernatants and intracellular extracts of 36 LAB isolated from meat and dairy products were investigated. These bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to the genus Enterococcus. Three isolates were identified as E. hirae, one isolate as Enterococcus sp., 17 as E. faecium and 15 as E. faecalis. Antimicrobial activity against the indicator microorganism Listeria monocytogenes was observed for 21 supernatants culture, it is highlighted with the largest inhibition zones the strains IS196 (10.7 mm) and IS197 (11.0 mm), and 7 strains using cell extracts, showed the highest inhibition zones. Strains IS196 (9.7 mm) and IS197 (9.3 mm) were identified as E. faecium. Evaluation of antioxidant activity was performed by three different methods. The 36 isolates showed antioxidant activity to determination Thiobarbituric Acid Reactive Substances (TBARS) method with supernatant culture and cell-free extract. Antioxidant capacity was also observed for the scavenger of free radicals by the method of ABTS (2,2-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and the capture of the •+radical DPPH (2,2-diphenyl-1 - picrylhydrazyl). These two methods showed that only supernatant culture samples had antioxidant capacity. The highest antimicrobial and antioxidant activities were observed by E. faecium, IS196 and IS197. It also was performed the enrichment of Enterococcus species with Selenium (Sodium selenite - Se(IV)). In these study, it was selected the isolates with highest selenium bioaccumulation capacity, LAB 14 and LAB 18, identified as E. faecalis and E. faecium, respectively. The isolates had high growth at 35ºC for 24 h (DO BAL 14=1.4 and BAL 18=1.5), and the Se(IV) removal was maximum 600at inicial pH 7.0 and 25ºC. Time course experiment showed that both LAB 14 and LAB 18 had highest biomass production (OD=1.42 and 1.41) and Se(IV) 600bioremoval (14.89 and 14.79 mg L) respectively -1after 8 h of incubation. Substantial amount of selenium was detected in biomass of E. faecium (0.4599 mg g-1 of dry weight and E. faecalis (0.4759 mg g-1 of dry weight). These results showed that these bacteria can particularly help to reduce or inhibit pathogenic microorganisms, in the inhibition of oxidative spoilage in foods and animal feed, as well as, reduce oxidative damage caused by free radical production in living organisms. The significant uptake of Se(IV) by the Enterococcus species observed in this study, indicate that they can be used to deliver dietary selenium through feed augmentation with Se(IV)-enriched Enterococcus biomass.
426

Potencial probiótico de bactérias lácticas e atividades biológicas de leite e queijos de ovelha / Probiotic potential of lactic bacteria and biological activities of ewe´s milk and cheeses

Meira, Stela Maris Meiste January 2011 (has links)
Bactérias lácticas probióticas e peptídeos bioativos são importantes componentes de alimentos funcionais. Neste trabalho, bactérias lácticas isoladas de leite ovino cru e de queijo de ovelha foram identificadas por 16S rDNA como pertencentes ao gênero Lactobacillus e avaliadas quanto ao potencial probiótico. Todas as linhagens demonstraram adequada tolerância ao pH 3,0 e a sais biliares em concentrações de até 0,5%. A linhagem LCN 56, quando exposta ao tratamento de pH 2,0 e pepsina, adicionado de leite desnatado, não teve sua viabilidade reduzida durante 4 horas em função do efeito protetor do alimento. Adicionalmente, propriedades de autoagregação e hidrofobicidade, atividades antioxidante e antibacteriana, e ainda, produção da enzima β-galactosidase foram avaliadas em 12 Lactobacillus e em 2 linhagens de referência. Estas características foram bastante variáveis entre as linhagens, mesmo entre aquelas pertencentes à mesma espécie. Nenhuma das bactérias exibiu todas as propriedades desejáveis, porém dois isolados apresentaram conjuntamente o maior número de atributos funcionais, L. brevis SM-B e L. plantarum SM-I. Com relação aos peptídeos com atividade biológica, extratos aquosos de queijos de ovelha maturados foram avaliados e apresentaram propriedades antioxidantes de sequestro do cátion radical 2,2 azino-bis (3-etilbenzotiazolino-6-ácido sulfônico) (ABTS) e atividade quelante de ferro bastante variáveis, enquanto as análises de poder redutor e substâncias reativas ao ácido tiobarbitúrico (TBARS) apresentaram similaridade para a maioria dos queijos. A atividade inibitória da enzima conversora de angiotensina foi elevada, em contraste à atividade antibacteriana que não foi encontrada em nenhuma das amostras. Os resultados encontrados podem ser atribuídos a possíveis peptídeos bioativos presentes. O perfil proteico do extrato aquoso correspondente ao queijo Roquefort foi visualizado por SDS-PAGE, por ter sido a amostra com a melhor intensidade das bioatividades. Portanto, os resultados refletem a potencial funcionalidade dos produtos lácteos ovinos. / Probiotic lactic bacteria and bioactive peptides are important components of functional foods. In this work, lactic bacteria isolated from raw ovine milk and cheese were identified by 16S rDNA as belonging to Lactobacillus genus and evaluated for probiotic potential. All strains demonstrated appropriate tolerance to pH 3.0 and bile salts until 0.5% of concentration. The strain LCN 56, when exposed to the treatment of pH 2.0 and pepsin added with skim milk, did not reduce viability during 4 hours due to protective effect of the food. Additionaly, autoaggregation and hydrophobicity properties, antioxidant and antibacterial activities and also β-galactosidase production were evaluated for 12 lactobacilli and for 2 reference strains. These characteristics were quite variable among strains, even among strains belonging to the same species. None of them exhibited all the desired properties, but two strains showed the greatest number of functional attributes together, L. brevis SM-B and L. plantarum SM-I. In relation to peptides with biological activity, water soluble extracts of ewe´s ripened cheeses were evaluated and presented antioxidant properties of scavenging of the cation radical 2,2‘-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and iron chelating activity quite variable, whereas power reduction and thiobarbituric acid reactive substances (TBARS) analysis presented similarity for the major of the cheeses. Inhibition of the angiotensin-converting enzyme (ACE) was elevated, in contrast to antibacterial activity that was not found for any sample. The results found can be attributed for the possible presence of bioactive peptides. The protein pattern of water soluble extract corresponding to Roquefort was visualized by SDS-PAGE for being the sample that displayed the best bioativities. Therefore, the results reflect potential functionality of dairy sheep.
427

Efeito do consumo de probióticos em fatores associados com progressão da doença renal crônica e risco cardiovascular

Moreira, Thais Rodrigues January 2018 (has links)
Introdução: O trato gastrointestinal humano é composto por uma comunidade microbiana diversificada que atua no controle da saúde. Estudos recentes demonstraram que o equilíbrio da microbiota intestinal é afetado na doença renal crônica (DRC), ocasionando o quadro de disbiose intestinal. Estes estudos sugeriram uma associação da disbiose intestinal com complicações metabólicas como acúmulo de toxinas urêmicas, progressão da DRC, inflamação e risco cardiovascular. Diante disso, medidas com o objetivo de restaurar o equilíbrio da microbiota intestinal são sugeridas, tais como a ingestão oral de probióticos, mas poucos estudos têm abordado o efeito destes suplementos na progressão da DRC e no risco cardiovascular destes pacientes. Objetivo: Avaliar o efeito do consumo de probióticos em fatores associados com progressão da DRC e risco cardiovascular de pacientes com DRC. Material e métodos: Trata-se de um estudo clínico controlado por placebo registrado no Clinical Trials NCT03400228. O estudo incluiu 30 pacientes adultos com DRC nos estágios 3 a 5 não em diálise, com função renal estável e proteinúria igual ou superior a 500 mg. A coleta de dados ocorreu entre novembro de 2015 até dezembro de 2017. O protocolo do estudo constou de período de washout de 4 semanas e randomização dos pacientes para o grupo de intervenção (GI, suplemento com probiótico) ou para o grupo controle (GC, maltodextrina). Foi realizado avaliação basal e após 24 semanas de consumo de probiótico ou placebo. Todos os pacientes receberam a orientação de consumir 2 sachês por dia do probiótico ou do placebo (maltodextrina). Foram avaliadas variáveis demográficas, clínicas, nutricionais, hábito intestinal e exames laboratoriais com amostras sanguíneas e urinárias. Resultados: Dos 30 pacientes incluídos, 20 completaram as 24 semanas do estudo, sendo 10 no grupo intervenção e 10 no grupo placebo. Após o uso de probiótico houve aumento na taxa de filtração glomerular estimada (p<0,001) e diminuição nos níveis séricos de creatinina (p<0,001), ureia (p=0,015), proteína C reativa (p=0,03), hormônio da paratireóide (p=0,03) e potássio (p=0,012), em comparação ao grupo placebo. Os efeitos positivos do probiótico na taxa de filtração glomerular estimada e na diminuição dos níveis séricos de creatinina e ureia permaneceram após análise de regressão multivariada. Não houveram diferenças significativas nos parâmetros urinários entre os grupos. Sintomas de constipação (p<0,001) e consistência fecal (p=0,016) apresentaram melhora no grupo intervenção versus placebo. Conclusão: A suplementação de probióticos melhorou os marcadores de função renal e reduziu inflamação, além de auxiliar na melhora dos sintomas de constipação intestinal em pacientes com DRC. / Introduction: The human gastrointestinal tract is colonized by a diversified microbial community that acts in control of health. Recent studies have shown that intestinal microbiota balance is affected in chronic kidney disease (CKD) leading to intestinal dysbiosis. These studies have suggested association of intestinal dysbiosis with several metabolic disorders such as accumulation of uremic toxins, progression of CKD, inflammation and cardiovascular risk. Therefore, interventional measurement that improve intestinal microbiota balance are suggested such as supplementation of probiotics, however few studies evaluated the effect of these supplements on the progression of CKD and cardiovascular risk in CKD patients. Aim: The purpose of the study was to evaluate the effects of probiotic supplementation on the factors associated with progression of CKD and cardiovascular risk in patients with CKD. Desing and Methods: This was a randomized, double-blind, placebo-controlled study. Thirty patients with CKD stages 3 to 5 not on dialysis, with stable renal function and protein-creatinine ratio > 0.50 were included. Data collection was between November 2015 and December 2017. Study protocol was 4-week washout period, patients randomized to intervention group (IG, probiotic supplement) or control group (CG, maltodextrin), and follow for 24 weeks. Renal function, C-reactive protein (CRP), bone and mineral metabolism, nutritional, and lipid profile markers and intestinal habit were measured at baseline and 24 weeks of study. Results: From 30 patients included in this study, 20 completed the 24 study weeks, 10 in the TG and 10 in PG. After probiotic supplementation, there was increase in estimated glomerular filtration rate (p<0.001) and decrease in serum creatinine 8 (p<0.001), urea (p=0.015), C-reactive protein (p=0.030), parathyroid hormone (p=0.03), and potassium (p=0.012) levels compared to CG. The beneficials effects of probiotics on estimated glomerular filtration rate and serum creatinine, urea, and Creactive protein remained after multivariate linear regression. There were no significant differences in the urinary parameters between the two groups. Symptoms of constipation (p<0.001) and stool consistency (p=0.016) improved in IG compared to CG. Conclusion: Probiotic supplementation improved markers of renal function and reduced inflammation. In addition, it improved the symptoms of intestinal constipation in patients with CKD.
428

Anticorpos policlonais, leveduras vivas e monensina sódica em dietas de alto concentrado para bovinos confinados

Rodrigues, Érico [UNESP] 07 June 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:34Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-07Bitstream added on 2014-06-13T21:06:29Z : No. of bitstreams: 1 rodrigues_e_dr_botfmvz.pdf: 757118 bytes, checksum: 8b4ac338061cf6ba7fd00cd910adc25d (MD5) / Universidade Estadual Paulista (UNESP) / O objetivo deste estudo foi avaliar os efeitos da alimentação de bovinos da raça Nelore com dietas de alto concentrado com preparado anticorpo policlonal (PAP), leveduras vivas - Saccharomyces cerevisae (LEV), monensina sódica (MON), associação entre PAP e LEV (MIX) e sem aditivos - controle (CTL) no desempenho, características de carcaça e custo do quilograma de peso vivo ganho em confinamento. Foram utilizados 95 bovinos Nelore, não castrados, com 20 meses de idade, oriundos de recria a pasto, terminados em confinamento por 112 dias com dietas de alto concentrado iso-protéicas e iso-energéticas. Não houve efeito (P>0,05) do ionóforo MON sobre ingestão de matéria seca durante o período de confinamento, porém a MON exerceu efeito (P<0,05) reduzindo a ingestão de matéria seca em percentagem do peso vivo nos primeiros 28 dias de confinamento em relação aos demais aditivos alimentares. Não houve efeito (P>0,05) do ionóforo MON em relação ao ganho de peso médio diário ao longo do confinamento, mais houve efeito negativo (P<0,05) do aditivo LEV, que diminuiu o ganho de peso dos animais ao longo do período de confinamento, consequentemente apresentou uma pior (P>0,05) conversão alimentar e um maior (P>0,05) custo para o quilo ganho em confinamento. O fornecimento de leveduras vivas também propiciou menor (P<0,05) peso de carcaça quente e peso de carcaça em arrobas. Os animais que receberam os aditivos alimentares PAP e LEV apresentaram (P<0,05) menor quantidade de gordura visceral na carcaça em relação aos animais que receberam MON. A utilização de PAP e LEV não alteram (P>0,05) as medidas de área de olho de lombo (AOL), espessura de gordura subcutânea (EGS) e espessura de gordura subcutânea do músculo Biceps femoris (EGG) em relação à MON e CTL / The objective of this study was to evaluate the effects of feeding Nellore bullocks with high concentrate diets containing: polyclonal antibody preparation (PAP), live yeast - Saccharomyces cerevisae (LEV), sodic monensin (MON), the association of PAP e LEV (MIX) and a control group on performance, carcass traits, and cost of gain. The diets were iso-energetic and iso-proteic and the feeding period was 112 days. There was no effect (P>0.05) of feeding ionophores on dry matter intake during total feeding period, however MON reduced (P<0.05) dry matter intake as body weight percentage in the first 28 days, compared to the others feed additives. There was no effect (P>0.05) of feeding MON in averaged daily gain, but on the other hand, there was found a negative effect (P<0.05) of feeding LEV, which decreased averaged daily gain, increased feed conversion and cost of gain. The addition of LEV in the diets also decreased (P<0.05) hot carcass weight. Animals that received PAP and LEV presented (P<0.05) less visceral fat than MON. The inclusion of PAP and LEV did not altered (P>0.05) ultrasound measurements compared to MON and CTL
429

Avaliação das atividades antimicrobiana, antioxidante e capacidade de bioacumulação de selênio em células de Enterococcus

Pieniz, Simone January 2010 (has links)
As bactérias ácido lácticas (BAL) possuem papel importante em uma ampla variedade de alimentos, incluindo produtos lácteos e cárneos. Neste trabalho foram investigadas as atividades antimicrobiana e antioxidante, do sobrenadante bruto e do extrato intracelular, de 36 BAL isoladas de produtos lácteos e cárneos. Estas bactérias foram identificadas através do seqüenciamento do rRNA da região 16S. A análise através do GenBank BLAST revelou que todos os isolados pertencem ao gênero Enterococcus. Três isolados foram identificados como E. hirae, um isolado como Enterococcus sp., 17 como E. faecium e 15 como E. faecalis. A atividade antimicrobiana frente ao microrganismo indicador Listeria monocytogenes foi observado em 21 isolados, utilizando o sobrenadante bruto, destacando-se com os maiores halos de inibição os isolados IS 196 (10,7 mm) e IS 197 (11,0 mm) e, em 7 isolados, utilizando o extrato intracelular, os maiores halos de inibição foram obtidos com os isolados IS 196 (9,7 mm) e IS 197 (9,3 mm), sendo estes dois isolados identificados como E. faecium. A avaliação da atividade antioxidante foi realizada por três métodos distintos. Os 36 isolados apresentaram atividade antioxidante pela determinação às Substâncias Reativas ao Ácido Tiobarbiturico (TBARS), utilizando tanto o sobrenadante bruto quanto o extrato intracelular. A A capacidade antioxidante também foi verificada pelo seqüestro de radicais livres através do método de ABTS (2,2 azino-bis (3-•+etilbenzotiazolino-6-ácido sulfônico)) e pela captura do radical DPPH (2,2-difenil-1-picrilhidrazil). Nestes dois métodos verificou-se que apenas as amostras do sobrenadante bruto demonstraram capacidade antioxidante. A atividade antioxidante mais elevada foi observada nos isolados IS 196 e IS 197. Foi realizado também o enriquecimento das espécies de Enterococcus com selênio (Selenito de Sódio - Se(IV)). Neste estudo, selecionaram-se os isolados que bioacumularam maior concentração de Se(IV) na biomassa, BAL 14 e BAL 18, identificados como E. faecalis e E. faecium, respectivamente. Os isolados tiveram ótimo crescimento à 35ºC por 24 h (DO BAL 14=1,4 e BAL 18=1,5), a remoção 600ótima do selênio foi verificada com o pH inicial de 7,0 e temperatura de 25ºC. Através da curva de crescimento observou-se que após 8 h de incubação, as culturas BAL 14 e BAL 18 apresentaram a maior produção de biomassa (DO=1,42 e 1,41) e bioremoção do Se(IV) (14,89 e 14,79 mg L), 600-1respectivamente. Quantidade considerável de selênio foi detectada na biomassa de E. faecium (0,4599 mg g de peso seco e E. faecalis (0,4759 mg g de peso -1-1seco). Estes resultados mostram que estas bactérias podem auxiliar particularmente na redução ou inibição de microrganismos patogênicos, na inibição da oxidação de alimentos e ração animal, bem como reduzir os danos oxidativos provocados pela produção de radicais livres nos organismos vivos. A absorção significativa de Se(IV) pelas espécies de Enterococcus observados neste estudo, indicam que estes microrganismos podem ser utilizados para estudos posteriores visando à suplementação alimentar animal, através da utilização da biomassa produzida pelos Enterococcus enriquecidos com Se(IV). / The lactic acid bacteria (LAB) have an important role in a wide variety of foods, including dairy products, meat and fermented foods. In this study, antimicrobial and antioxidant activities of culture supernatants and intracellular extracts of 36 LAB isolated from meat and dairy products were investigated. These bacterial were identified by 16S rRNA sequencing. GenBank BLAST analysis revealed that all the isolates belong to the genus Enterococcus. Three isolates were identified as E. hirae, one isolate as Enterococcus sp., 17 as E. faecium and 15 as E. faecalis. Antimicrobial activity against the indicator microorganism Listeria monocytogenes was observed for 21 supernatants culture, it is highlighted with the largest inhibition zones the strains IS196 (10.7 mm) and IS197 (11.0 mm), and 7 strains using cell extracts, showed the highest inhibition zones. Strains IS196 (9.7 mm) and IS197 (9.3 mm) were identified as E. faecium. Evaluation of antioxidant activity was performed by three different methods. The 36 isolates showed antioxidant activity to determination Thiobarbituric Acid Reactive Substances (TBARS) method with supernatant culture and cell-free extract. Antioxidant capacity was also observed for the scavenger of free radicals by the method of ABTS (2,2-bis-(3-ethylbenzothiazoline-6-sulfonic acid)) and the capture of the •+radical DPPH (2,2-diphenyl-1 - picrylhydrazyl). These two methods showed that only supernatant culture samples had antioxidant capacity. The highest antimicrobial and antioxidant activities were observed by E. faecium, IS196 and IS197. It also was performed the enrichment of Enterococcus species with Selenium (Sodium selenite - Se(IV)). In these study, it was selected the isolates with highest selenium bioaccumulation capacity, LAB 14 and LAB 18, identified as E. faecalis and E. faecium, respectively. The isolates had high growth at 35ºC for 24 h (DO BAL 14=1.4 and BAL 18=1.5), and the Se(IV) removal was maximum 600at inicial pH 7.0 and 25ºC. Time course experiment showed that both LAB 14 and LAB 18 had highest biomass production (OD=1.42 and 1.41) and Se(IV) 600bioremoval (14.89 and 14.79 mg L) respectively -1after 8 h of incubation. Substantial amount of selenium was detected in biomass of E. faecium (0.4599 mg g-1 of dry weight and E. faecalis (0.4759 mg g-1 of dry weight). These results showed that these bacteria can particularly help to reduce or inhibit pathogenic microorganisms, in the inhibition of oxidative spoilage in foods and animal feed, as well as, reduce oxidative damage caused by free radical production in living organisms. The significant uptake of Se(IV) by the Enterococcus species observed in this study, indicate that they can be used to deliver dietary selenium through feed augmentation with Se(IV)-enriched Enterococcus biomass.
430

Potencial probiótico de bactérias lácticas e atividades biológicas de leite e queijos de ovelha / Probiotic potential of lactic bacteria and biological activities of ewe´s milk and cheeses

Meira, Stela Maris Meiste January 2011 (has links)
Bactérias lácticas probióticas e peptídeos bioativos são importantes componentes de alimentos funcionais. Neste trabalho, bactérias lácticas isoladas de leite ovino cru e de queijo de ovelha foram identificadas por 16S rDNA como pertencentes ao gênero Lactobacillus e avaliadas quanto ao potencial probiótico. Todas as linhagens demonstraram adequada tolerância ao pH 3,0 e a sais biliares em concentrações de até 0,5%. A linhagem LCN 56, quando exposta ao tratamento de pH 2,0 e pepsina, adicionado de leite desnatado, não teve sua viabilidade reduzida durante 4 horas em função do efeito protetor do alimento. Adicionalmente, propriedades de autoagregação e hidrofobicidade, atividades antioxidante e antibacteriana, e ainda, produção da enzima β-galactosidase foram avaliadas em 12 Lactobacillus e em 2 linhagens de referência. Estas características foram bastante variáveis entre as linhagens, mesmo entre aquelas pertencentes à mesma espécie. Nenhuma das bactérias exibiu todas as propriedades desejáveis, porém dois isolados apresentaram conjuntamente o maior número de atributos funcionais, L. brevis SM-B e L. plantarum SM-I. Com relação aos peptídeos com atividade biológica, extratos aquosos de queijos de ovelha maturados foram avaliados e apresentaram propriedades antioxidantes de sequestro do cátion radical 2,2 azino-bis (3-etilbenzotiazolino-6-ácido sulfônico) (ABTS) e atividade quelante de ferro bastante variáveis, enquanto as análises de poder redutor e substâncias reativas ao ácido tiobarbitúrico (TBARS) apresentaram similaridade para a maioria dos queijos. A atividade inibitória da enzima conversora de angiotensina foi elevada, em contraste à atividade antibacteriana que não foi encontrada em nenhuma das amostras. Os resultados encontrados podem ser atribuídos a possíveis peptídeos bioativos presentes. O perfil proteico do extrato aquoso correspondente ao queijo Roquefort foi visualizado por SDS-PAGE, por ter sido a amostra com a melhor intensidade das bioatividades. Portanto, os resultados refletem a potencial funcionalidade dos produtos lácteos ovinos. / Probiotic lactic bacteria and bioactive peptides are important components of functional foods. In this work, lactic bacteria isolated from raw ovine milk and cheese were identified by 16S rDNA as belonging to Lactobacillus genus and evaluated for probiotic potential. All strains demonstrated appropriate tolerance to pH 3.0 and bile salts until 0.5% of concentration. The strain LCN 56, when exposed to the treatment of pH 2.0 and pepsin added with skim milk, did not reduce viability during 4 hours due to protective effect of the food. Additionaly, autoaggregation and hydrophobicity properties, antioxidant and antibacterial activities and also β-galactosidase production were evaluated for 12 lactobacilli and for 2 reference strains. These characteristics were quite variable among strains, even among strains belonging to the same species. None of them exhibited all the desired properties, but two strains showed the greatest number of functional attributes together, L. brevis SM-B and L. plantarum SM-I. In relation to peptides with biological activity, water soluble extracts of ewe´s ripened cheeses were evaluated and presented antioxidant properties of scavenging of the cation radical 2,2‘-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and iron chelating activity quite variable, whereas power reduction and thiobarbituric acid reactive substances (TBARS) analysis presented similarity for the major of the cheeses. Inhibition of the angiotensin-converting enzyme (ACE) was elevated, in contrast to antibacterial activity that was not found for any sample. The results found can be attributed for the possible presence of bioactive peptides. The protein pattern of water soluble extract corresponding to Roquefort was visualized by SDS-PAGE for being the sample that displayed the best bioativities. Therefore, the results reflect potential functionality of dairy sheep.

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