Lactic acid bacteria were isolated from 10 samples of the traditionally fermented foods (5 samples of Vietnamese fermented pork roll and 5 samples of the salted field cabbage) and 5 samples of fresh cow milks collected from households in Vietnam. 22 strains of lactic acid bacteria were isolated for inhibition to Lactobacillus plantarum JCM 1149. Of these, only 2 strains including DC1.8 and NC1.2 have rod shape, the others have coccus shape. 7 strains showing higher antibacterial activity were selected for checking spectrum of antibacteria with indicator bacteria consistting of Bacillus subtilis ATCC 6633, Enterococcus faecium JCM 5804 and Staphylococcus aureus TLU. By which, 3 strains including NC3.5 (from Vietnamese fermented pork roll), DC1.8 (from salted field cabbage) and MC3.19 (from fresh cow milk) were selected because of their higher antibacterial ability. However, the antibacterial activity of the lactic acid bacteria can be based on their disposable compounds and some other antibacterial compounds produced during their growth (such as lactic acid, H2O2, bacteriocins, etc.). For seeking lactic acid bacteria with capability of producing bacteriocins, antibacterial compounds with protein nature, 3 above strains were checked sensitiveness to proteases (including protease K, papain, α – chymotrypsin and trypsin). Because bacteriocins are proteinaceous antibacterial compounds, so their antibacterial activity will be reduced if proteases are added. The result showed DC1.8 and MC3.19 were capable of producing bacteriocin during culture process. They were identified as Lactobacillus acidophilus and Lactococcus lactis and classified, respectively, based on analysis chemical characterisitcs by standard API 50 CHL kit and phylogeny relationship by 16s rRNA sequences. / Các chủng vi khuẩn lactic được phân lập từ 10 mẫu thực phẩm lên men truyền thống (5 mẫu nem chua, 5 mẫu dưa cải bẹ muối) và 5 mẫu sữa bò tươi được thu thập từ các hộ gia đình ở Việt Nam. 22 chủng vi khuẩn lactic đã được phân lập với tiêu chí có khả năng kháng lại vi khuẩn kiểm định Lactobacillus plantarum JCM 1149. Trong số đó, 2 chủng DC1.8 và NC1.2 có tế bào hình que, các chủng còn lại có tế bào hình cầu. 7 chủng thể hiện hoạt tính kháng khuẩn cao được lựa chọn để xác định phổ kháng khuẩn rộng hơn với ba loài vi khuẩn kiểm định Bacillus subtilis ATCC 6633, Enterococcus faecium JCM 5804 và Staphylococcus aureus TLU. Từ đó lựa chọn được 3 chủng có hoạt tính kháng khuẩn cao hơn hẳn. Các chủng này gồm NC3.5 phân lập từ nem chua, DC1.8 phân lập từ dưa cải bẹ muối và MC3.19 phân lập từ sữa bò tươi. Tuy nhiên, hoạt tính kháng khuẩn của vi khuẩn lactic bao gồm những hợp chất nội tại có trong nó và cả những hợp chất được sinh ra trong quá trình phát triển của nó (như axit lactic, H2O2, bacteriocin, …). Với định hướng tìm chủng vi khuẩn lactic có khả năng sinh bacteriocin, chất kháng khuẩn có bản chất protein, 3 chủng trên được kiểm tra độ nhạy cảm với các protease (gồm protease K, papain, α – chymotrypsin và trypsin). Do bacteriocin là chất kháng khuẩn có bản chất protein nên hoạt tính kháng khuẩn của chúng sẽ bị giảm nếu protease được bổ xung vào. Kết quả lựa chọn được chủng DC1.8 và MC3.19 có khả năng sinh bacteriocin. Hai chủng này được phân loại đến loài nhờ vào phân tích đặc điểm sinh hóa bằng kit API 50 CHL và mối quan hệ di truyền thông qua trình tự gen 16s rRNA. Kết quả phân loại đã xác định chủng DC1.8 thuộc loài Lactobacillus acidophilus và chủng MC3.19 thuộc loài Lactococcus lactis.

The Diploma thesis deals with designing of probiotic dietary supplement for children with strains Lactobacillus acidophilus and Bifidobacterium breve and with prebiotics. Used prebiotics were Inulin, Chia fiber, Bamboo fiber, Chlorella + Spirulina and Yakon syrup. The theoretical part is focused on probiotics, prebiotics and their biological influence. In experimental part the possibilities of encapsulation into alginate particle and lyophilisation of probiotic cells were observed to find their good form to final nutritional product for children. Several types of probiotic with addition of prebiotics were tested in model conditions of gastrointestinal tract. It was found that addition of prebiotic highly increases viability of probiotic cells and their resistance to model conditions of gastrointestinal tract. In this case, the best prebiotic was found in Yakon syrup. The prebiotics were also characterised in terms of nutritional composition, amount of total and reducing sugars, oligosaccharides, proteins, lipids, polyphenols and chlorophyll were obtained. Finally, Chia fiber, Chlorella + Spirulina and Yakon syrup were chosen as prebiotics with best characterisation/properties. In conclusion, a dietary supplement with lyophilized alginate particles containing probiotic cells and with the most appropriate prebiotics were designed. Forms of the product were powder and gummy-bear.

The presented diploma thesis is focused on the preparation and the monitoring of the biological stability of beer enriched with probiotics. Probiotic bacterial strains of Lactobacillus acidophilus, Bifidobacterium breve and Bifidobacterium bifidum were used in this study. The theoretical part is divided into two sections. In the first section, probiotics are generally characterized, and their role within a gut microbiota is described. Next, the microbiology of particular probiotic microorganisms including the genera of Lactobacillus and Bifidobacterium is described. Then, some factors influencing the viability and the growth of probiotics are stated. In this section, biological effects of probiotics on the human organism and their potential clinical applications are described. The second section of the theoretical part deals with the technology of brewing, the chemical composition of beer and particular beer styles. In the experimental part, the methods of probiotic bacterial cell concentration and viability determination were optimized. Several techniques for determination of these parameters were selected, particularly the cultivation method, flow cytometry and the spectrophotometric measurement of turbidity. Then, the growth curves of the probiotic strains were measured in MRS medium. Probiotic bacteria were cultivated in model beer samples, i.e. in MRS media with several different concentrations of ethanol. It is possible to say that ethanol did not have significant effect on probiotics growth. Next, experimental cultivations of individual probiotic bacteria and their mixtures in nine real beer samples were conducted. No increase of viable cells concentrations was detected in the samples. On the contrary, a decrease of the concentrations was observed, mainly in the samples with individual bacterial strains. However, certain values of viable cells concentrations were determined at the end of the cultivations in all cases. A pale, top-fermented beer was brewed and supplemented with probiotics, and the concentrations of viable probiotic cells were monitored during 37 days of fermentation. A decrease of concentrations by two orders of magnitude of CFU/ml was observed in almost all samples. Yet, viable cells of probiotic bacteria were detected in all samples of beer at the end of the fermentation. Maximal concentration of viable probiotic cells in the brewed beer was determined with the cultivation method at (3,80 ± 0,14)10^5 CFU/ml. Chosen samples were analyzed with HPLC-RI method that quantified the common beer concentrations of ethanol in all chosen samples, lactic acid was not detected. Sensory analysis was conducted as well. Based on the results of the experimental part and the bibliography, an optimal technology of the preparation of beer enriched with probiotics is discussed in this study.

This diploma thesis is focused on encapsulation probiotics and co-encapsulation with some types of prebiotics. In theoretical part is aimed to probiotics, their general characteristics and application of probiotics in food industry. There are described prebiotics and their classification, there is described principles of encapsulation and encapsulation techniques. Methods, which are used for analysis of particles and encapsulation components were introduced too. The experimental part describes methods of prebiotics characterization by high performance liquid chromatography, thin layer chromatography and spectrophotometric methods. Cultivation of probiotics with prebiotics - hydrolyzed and non-hydrolyzed wad tested. Using flow cytometry cell viability was measured too. Finally probiotics and prebiotics were encapsulated, mainly by encapsulator machine. Long-term stability of particles during 6 week storage was observed. The particles were exposed to effect of artificial intestinal, gastric and bile juices.

The Diploma thesis deals with use of selected probiotic strains Lactobacillus acidophilus and Bifidobacterium breve in different forms in food for infants. The theoretical part is focused on describing probiotics, encapsulation methods and intestinal gut microbiota of infants. Further, characterization of individual periods of infant feeding and food for infants were introduced. In experimental part the possibilities of encapsulation and lyophilisation of probiotic cells were observed. Probiotic cells were encapsulated into alginate particles. The encapsulator was used for preparation of particles and the most appropriate particles were prepared by encapsulation nozzle with size of 300 µm. Moreover, probiotics viability was monitored by Flow Cytometry, Fluorescence Microscopy and by cultivation (CFU method). Viability of probiotics was monitored during long-term storage in selected food for infants. The appropriate shelf life of non-lyophilized alginate particles in real food have been set at 1 to 2 months. Lyophilized alginate particles could be stored for more than 3 months. Finally, the stability of the particles and viability of encapsulated and non-encapsulated cells in the gastrointestinal tract conditions were also examined. The viabilities of lyophilized cells and cells encapsulated in lyophilized particles were also compared. From the results obtained, non-encapsulated probiotic bacteria cells are more susceptible to negative effects of digestive juices, the percentage of dead probiotic cells after digestion was approximately 80 %. On the other hand, alginate particles showed cell protection from digestive juices, after incomplete cell releasing from particles the percentage of dead probiotic cells did not exceed 20 %. After adequate rehydration, similar results were gained with lyophilized alginate particles. Lyophilized alginate particles have been determined to be the most suitable application form for infants’ food.

No description available.

Foram conduzidos três experimentos no confinamento experimental do Departamento de Zootecnia da ESALQ/USP com o objetivo de estudar os efeitos de diferentes aditivos em rações para bovinos terminados em confinamento. No experimento 1 foram utilizados 100 bovinos machos Nelore castrados (392 kg), distribuídos em 20 baias, por 60 dias. As rações continham 41% de sorgo moído, 40% de polpa cítrica peletizada e 15% de silagem de cana-de-açúcar. Os tratamentos foram: (1) controle, (2) monesina sódica Rumensin (MON1), (3) monensina sódica Rumenfort (MON2), levedura Saccharomyces cerevisiae Yea-Sacc 1026 (LEV1) e levedura Saccharomyces cerevisiae Biosaf SC47 (LEV2). A IMS foi reduzida pelo tratamento MON1 (P<0,05), quando comparada ao tratamento controle. O GPD dos animais não foi afetado pelos tratamentos (P>0,05). A EA dos animais não foi afetada pelos tratamentos (P>0,05). O tratamento MON2 apresentou um menor rendimento de carcaça (P<0,05) e o tratamento MON 1 apresentou uma maior AOL (P<0,05). No experimento 2 foram utilizados 96 tourinhos Nelore não castrados (396 kg), distribuídos em 16 baias por 95 dias. Os tratamentos foram: (1) Controle, (2) levedura Saccharomyces cerevisiae Biosaf SC47 (LEV), (3) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 1g /bovino/dia (PROB1) e (4) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 3g/bovino/dia (PROB2). As rações continham 59% de polpa cítrica peletizada, 35% de farelo de glúten de milho úmido e 5% de feno de tifton 65. A adição dos aditivos levedura (Saccharomyces cerevisae) e a combinação de leveduras e bactérias probióticas não afetou a IMS o GPD e a EA dos animais (P>0,05). A energia líquida de manutenção e de ganho das rações também não foi afetada pelos tratamentos (P>0,05), assim como os dados de carcaça. No experimento 3, que avaliou a digestibilidade das rações, foram utilizados 20 tourinhos Nelore, alocados em 20 baias individuais durante 15 dias, sendo 10 dias de adaptação ao marcador e 5 dias de coleta de fezes. A ração foi a mesma utilizada no experimento 2, e o marcador utilizado foi o óxido de cromo. Os tramentos utilizados foram: (1) Controle, (2) monensina sódica Rumenfort (MON), (3) levedura Saccharomyces cerevisiae Biosaf SC47 (LEV), (4) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 1g /bovino/dia (PROB1) e (5) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 3g/bovino/dia (PROB2). Os aditivos testados não afetaram as digestibilidades da MS, da MO, da FDN e da PB das rações (P>0,05). Com os resultados obtidos é possível afirmar que bovinos Nelore, castrados ou não, confinados com rações com altos teores de concentrado ricos em co-produtos como polpa cítrica e farelo de glúten de milho úmido não apresentam melhor desempenho nem melhor digestibilidade dos nutrientes quando suplementados com monensina sódica ou com micorganismos probióticos. / Three trials were conducted at the ESALQ/USP Animal Sciences Department experimental feedlot to evaluate the effects of different feed additives in feedlot finished cattle. On trial 1 100 Nellore steers (392kg) were allocated to 20 pens for 60 days. Experimental rations had 41% ground milo, 40% dried citrus pulp and 15% sugarcane silage. Treatments were: (1) control, (2) sodium monensin Rumensin (MON1), (3) sodium monensin Rumenfort (MON2), (4) yeast culture Saccharomyces cerevisiae Yea-Sacc 1026 (LEV1) and (5) yeast culture Saccharomyces cerevisiae Biosaf SC47 (LEV2). DMI was reduced by MON1 trestment (P<0,05) in relation to control. WDG was not affected by treatments (P>0,05). Treatments did not affect FE (P>0,05). Animals on treatment MON2 showed the lowest dressing percentage (DP) and those on MON1 showed the highest rib eye area (REA) (P<0,05). Trial 2 used 96 young Nellore bulls (396kg), allocated to 16 pens for 95 days. Treatments were: (1) control, (2) Saccharomyces cerevisiae Biosaf SC47 (LEV), (3) Saccharomyces cerevisiae and probiotic bacteria mix at 1g /animal/day dose (PROB1) and (4) Saccharomyces cerevisiae probiotic bacteria mix at 3g/animal/day dose (PROB2). Rations contained 59% dried citrus pulp, 35% wet corn gluten feed and 5% Tifton 65 hay. Treatments didnt affect DMI, WDG and FE (P>0,05). Rations net energy for maintenance and gain were also not affect by treatments (P>0,05), well as carcass data. Trial 3 utilized 20 young Nellore bulls allocated to individual pens for 15 days (10 days for adaptation to marker and 5 days for data collection) to evaluate rations digestibility. Experimental ration was the same utilized on trial 2, with chromium oxide as an external marker. Treatments were (1) control, (2) sodium monensin Rumenfort (MON1), (3) yeast culture Saccharomyces cerevisiae Biosaf SC47 (LEV), (4) Saccharomyces cerevisiae and probiotic bacteria mix at 1g /animal/day dose (PROB1) and (5) Saccharomyces cerevisiae probiotic bacteria mix at 3g/animal/day dose (PROB2). Treatments did not affect rations DM, OM, NDF and CP digestibilities (P>0,05). Results show that Nellore cattle, castrated or not, feedlot finished receiving rations with high levels of byproducts such as dried citrus pulp and wet corn gluten feed dont have higher performance nor better nutrients digestibility when supplemented with sodium monensin or probiotic microorganisms.

Made available in DSpace on 2016-06-02T19:02:44Z (GMT). No. of bitstreams: 1 6426.pdf: 2868015 bytes, checksum: e3bf13cc85e7606dc2d0f7dbb387ebaa (MD5) Previous issue date: 2014-11-24 / Financiadora de Estudos e Projetos / The evaluation of new materials and biomaterials modified with silver nanoparticles is a line of research that has been gaining strength in various knowledge areas including dentistry. Even considering international scientific publications, however, there are still few studies evaluating dental restoration materials that are modified with silver nanoparticles. Proposal: this study aimed to compare a photopolymerizable composite resin modified with an antimicrobial silver nanoparticle additive (an experimental resin), with the photopolymerizable composite resin in its unmodified form (a commercially available dental restoration material), by evaluating the in vitro antibacterial properties and also some of the primary physical properties of the resin. Methodology: composite resin disks were made for three experimental groups: unmodified resin (control group) and modified resin with different silver nanoparticle concentrations: 0.3% and 0.6% wt (groups 1 and 2). The antibacterial activity on the surface of the samples was evaluated by in vitro growth of of Streptococcus mutans and Lactobacillus acidophilus biofilms in a 20% sucrose medium, which is followed by counting the viable cells from the biofilms through serial dilutions after three incubation periods - 1, 4 and 7 days (n = 9). Optical transmittance was tested to measure the percentage of transmittance in the samples (n = 9). The surface roughness was evaluated using Atomic Force Microscopy (n = 9). The colour of the samples and the colour difference between the groups was measured in a colorimetry test according to the CIELab system. The presence of silver in the nanoparticle additive was analysed using X-Ray Fluorescence Spectroscopy. The quality of the dispersion and distribution of silver on the samples was analysed using Transmission Microscopy. The liberation of silver in artificial saliva was also evaluated in vitro after three incubation periods (60, 120 and 210 days) with agitation of the samples, using the Inductively Coupled Plasma Optical Emission Spectroscopy technique. Results: for the three incubation times, the number of viable cells was statistically lower in groups 1 and 2 than in the control group (p < 0.05), and groups 1 and 2 were not statistically different (p > 0.05) for the two bacterial species (ANOVA Two way/Tukey). There was no significant difference in optical transmittance between group 1 and the control (p > 0.05), and group 2 had a lower transmittance value than the other groups (p < 0.05) (ANOVA/Tukey). The analysis of the values of the arithmetic roughness, which was obtained using the NanoScope software, showed that there was no significant difference in surface roughness between the three groups (p > 0.05) (ANOVA/Tukey). From the measurements of the colours, the total colour difference (&#916;E) between all of the groups was higher than 1 (the minimum value that represents a colour alteration perceptible to human vision) and lower than 3,3 (critical &#916;E). The presence of silver in the nanoparticle additive was confirmed in the X-Ray Fluorescence test. Microscopic analysis showed good distribution of silver for groups 1 and 2 (with silver in the four quadrants of the regions analysed). The dispersion was better for group 1 than for group 2 (which showed a higher number of particle clusters). After the three incubation times, silver was not detected in the artificial saliva for the three groups or; if it was present, the concentration was below the limit of detection for this technique (< 0.02 mg/L). Conclusions: the antibacterial property on the surfaces of the experimental resins was verified for the two cariogenic bacteria considered. Furthermore, the addition of silver did not cause negative alterations to the resin modified with the lower concentration of nanoparticles, which makes the continuation of this study possible and valuable. / A avaliação de novos materiais e biomateriais modificados com nanopartículas de prata é uma linha de pesquisa que vem ganhando força em várias áreas do conhecimento, inclusive na área odontológica. Porém, mesmo considerando a publicação científica internacional, ainda há poucas pesquisas que avaliam materiais restauradores dentários modificados desta forma. Proposição: o propósito deste estudo foi comparar a resina composta fotopolimerizável modificada com um aditivo antimicrobiano nanoparticulado de prata (uma resina experimental), com a resina composta fotopolimerizável em sua forma não modificada, um material restaurador dentário disponível comercialmente, avaliando a propriedade antibacteriana, in vitro, e também algumas de suas principais propriedades físicas. Metodologia: foram confeccionados discos de resina composta para 3 grupos experimentais: resina não modificada (grupo controle), e resina modificada com diferentes concentrações de nanopartículas de prata, 0,3 e 0,6% (grupos 1 e 2). A atividade antibacteriana na superfície das amostras foi avaliada pelo crescimento in vitro de biofilme de Streptococcus mutans e Lactobacillus acidophilus em meio de cultura contendo 20% de sacarose, seguido de contagem de células viáveis provenientes dos biofilmes após 3 períodos de incubação, 1, 4 e 7 dias, através de diluições seriadas (n=9). Um ensaio de transmitância óptica foi realizado para medir a porcentagem de transmitância das amostras (n=9). A rugosidade superficial foi avaliada por Microscopia de Força Atômica (n=9). A cor das amostras e a diferença de cor entre os grupos foi medida em um ensaio de colorimetria considerando o sistema CIELab. A presença de prata no aditivo nanoparticulado foi analisada por meio da Espectrometria de Fluorescência de Raios X. A qualidade da dispersão e distribuição da prata nas amostras foi analisada através da Microscopia de Transmissão. Foi também avaliada a liberação de prata em saliva artificial, in vitro, após 3 períodos de incubação das amostras, sob agitação, 60, 120 e 210 dias, através da técnica de Espectrometria de Emissão Óptica por Plasma Acoplado Indutivamente. Resultados: para os 3 tempos de incubação, o número de células viáveis foi estatisticamente mais baixo nos grupos 1 e 2 do que no grupo controle (p < 0,05), e os grupos 1 e 2 não mostraram entre si diferença estatisticamente significante (p > 0,05), para as 2 espécies bacterianas (ANOVA Two way/Tukey). Não houve diferença significante na transmitância óptica entre o grupo 1 e o controle (p > 0,05), já o grupo 2 apresentou um valor de transmitância menor que os demais grupos (p < 0,05) (ANOVA/Tukey). A análise dos valores de rugosidade aritmética, obtidos através do software NanoScope, mostrou que não houve diferença significante na rugosidade superficial entre os 3 grupos (p > 0,05) (ANOVA/Tukey). A partir das medições de cores, a diferença total de cor (&#916;E) entre todos os grupos foi superior a 1 (valor mínimo que representa uma alteração de cor perceptível à visão humana) e inferior a 3,3 (&#916;E crítico). A presença de prata no aditivo nanoparticulado foi confirmada no ensaio de Fluorescência de Raios X. A análise microscópica demonstrou boa distribuição de prata para o grupo 1 e 2 (com prata nos 4 quadrantes das regiões analisadas), e a dispersão foi melhor para o grupo 1 do que para o grupo 2 (que apresentou maior número de aglomerados de partículas). Após os 3 tempos de incubação, não foi detectada a presença de prata na saliva artificial, para os 3 grupos, sendo que, se presente, ela encontrava-se em uma concentração abaixo do limite de detecção da técnica (< 0,02 mg/L). Conclusões: a propriedade antibacteriana foi verificada nas superfícies das resinas experimentais para as duas espécies bacterianas cariogênicas consideradas, e a adição de prata não provocou alterações negativas na resina modificada com a menor concentração de nanopartículas, o que viabiliza a continuidade do estudo.

Foram conduzidos três experimentos no confinamento experimental do Departamento de Zootecnia da ESALQ/USP com o objetivo de estudar os efeitos de diferentes aditivos em rações para bovinos terminados em confinamento. No experimento 1 foram utilizados 100 bovinos machos Nelore castrados (392 kg), distribuídos em 20 baias, por 60 dias. As rações continham 41% de sorgo moído, 40% de polpa cítrica peletizada e 15% de silagem de cana-de-açúcar. Os tratamentos foram: (1) controle, (2) monesina sódica Rumensin (MON1), (3) monensina sódica Rumenfort (MON2), levedura Saccharomyces cerevisiae Yea-Sacc 1026 (LEV1) e levedura Saccharomyces cerevisiae Biosaf SC47 (LEV2). A IMS foi reduzida pelo tratamento MON1 (P<0,05), quando comparada ao tratamento controle. O GPD dos animais não foi afetado pelos tratamentos (P>0,05). A EA dos animais não foi afetada pelos tratamentos (P>0,05). O tratamento MON2 apresentou um menor rendimento de carcaça (P<0,05) e o tratamento MON 1 apresentou uma maior AOL (P<0,05). No experimento 2 foram utilizados 96 tourinhos Nelore não castrados (396 kg), distribuídos em 16 baias por 95 dias. Os tratamentos foram: (1) Controle, (2) levedura Saccharomyces cerevisiae Biosaf SC47 (LEV), (3) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 1g /bovino/dia (PROB1) e (4) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 3g/bovino/dia (PROB2). As rações continham 59% de polpa cítrica peletizada, 35% de farelo de glúten de milho úmido e 5% de feno de tifton 65. A adição dos aditivos levedura (Saccharomyces cerevisae) e a combinação de leveduras e bactérias probióticas não afetou a IMS o GPD e a EA dos animais (P>0,05). A energia líquida de manutenção e de ganho das rações também não foi afetada pelos tratamentos (P>0,05), assim como os dados de carcaça. No experimento 3, que avaliou a digestibilidade das rações, foram utilizados 20 tourinhos Nelore, alocados em 20 baias individuais durante 15 dias, sendo 10 dias de adaptação ao marcador e 5 dias de coleta de fezes. A ração foi a mesma utilizada no experimento 2, e o marcador utilizado foi o óxido de cromo. Os tramentos utilizados foram: (1) Controle, (2) monensina sódica Rumenfort (MON), (3) levedura Saccharomyces cerevisiae Biosaf SC47 (LEV), (4) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 1g /bovino/dia (PROB1) e (5) combinação de levedura Saccharomyces cerevisiae e bactérias probióticas na dose de 3g/bovino/dia (PROB2). Os aditivos testados não afetaram as digestibilidades da MS, da MO, da FDN e da PB das rações (P>0,05). Com os resultados obtidos é possível afirmar que bovinos Nelore, castrados ou não, confinados com rações com altos teores de concentrado ricos em co-produtos como polpa cítrica e farelo de glúten de milho úmido não apresentam melhor desempenho nem melhor digestibilidade dos nutrientes quando suplementados com monensina sódica ou com micorganismos probióticos. / Three trials were conducted at the ESALQ/USP Animal Sciences Department experimental feedlot to evaluate the effects of different feed additives in feedlot finished cattle. On trial 1 100 Nellore steers (392kg) were allocated to 20 pens for 60 days. Experimental rations had 41% ground milo, 40% dried citrus pulp and 15% sugarcane silage. Treatments were: (1) control, (2) sodium monensin Rumensin (MON1), (3) sodium monensin Rumenfort (MON2), (4) yeast culture Saccharomyces cerevisiae Yea-Sacc 1026 (LEV1) and (5) yeast culture Saccharomyces cerevisiae Biosaf SC47 (LEV2). DMI was reduced by MON1 trestment (P<0,05) in relation to control. WDG was not affected by treatments (P>0,05). Treatments did not affect FE (P>0,05). Animals on treatment MON2 showed the lowest dressing percentage (DP) and those on MON1 showed the highest rib eye area (REA) (P<0,05). Trial 2 used 96 young Nellore bulls (396kg), allocated to 16 pens for 95 days. Treatments were: (1) control, (2) Saccharomyces cerevisiae Biosaf SC47 (LEV), (3) Saccharomyces cerevisiae and probiotic bacteria mix at 1g /animal/day dose (PROB1) and (4) Saccharomyces cerevisiae probiotic bacteria mix at 3g/animal/day dose (PROB2). Rations contained 59% dried citrus pulp, 35% wet corn gluten feed and 5% Tifton 65 hay. Treatments didnt affect DMI, WDG and FE (P>0,05). Rations net energy for maintenance and gain were also not affect by treatments (P>0,05), well as carcass data. Trial 3 utilized 20 young Nellore bulls allocated to individual pens for 15 days (10 days for adaptation to marker and 5 days for data collection) to evaluate rations digestibility. Experimental ration was the same utilized on trial 2, with chromium oxide as an external marker. Treatments were (1) control, (2) sodium monensin Rumenfort (MON1), (3) yeast culture Saccharomyces cerevisiae Biosaf SC47 (LEV), (4) Saccharomyces cerevisiae and probiotic bacteria mix at 1g /animal/day dose (PROB1) and (5) Saccharomyces cerevisiae probiotic bacteria mix at 3g/animal/day dose (PROB2). Treatments did not affect rations DM, OM, NDF and CP digestibilities (P>0,05). Results show that Nellore cattle, castrated or not, feedlot finished receiving rations with high levels of byproducts such as dried citrus pulp and wet corn gluten feed dont have higher performance nor better nutrients digestibility when supplemented with sodium monensin or probiotic microorganisms.

Presented diploma thesis is focused on testing encapsulation methods of enzymes and probiotic bacteria. In the theoretical part a summary of different encapsulation techniques used in food industry is given. Further, materials for encapsulation, above all polysaccharides are presented. Next, some procedures of encapsulation of biopolymers and microorganisms – mainly enzymes and probiotic cultures are discussed. In the experimental part methods for preparation of several types of particles based on polysaccharides and liposomes are introduced. Particles were used for encapsulation of selected hydrolytic enzymes and probiotic strains Bifidobacterium breve a Lactobacillus acidophilus. The encapsulation effectiveness was evaluated by analysis of total proteins and enzyme activities. Particles sizes and their stability in water, in selected model foods and model body fluids were observed, too. According to results obtained in this work it was found that encapsulation of enzymes into polysaccharide particles were succesfull in all types of particles (encapsulation effectivness was more than 50 %). Polysaccharide particles showed a very good stability in body fluids as well as in model foods. As the most suitable materials for enzymes encapsulation chitosan and liposomes were found. Polysaccharide particles were used also for the encapsulation of microorganisms. The stability of particles with lactic acid bacteria was similar to particles containig enzymes, very good stability was verified aslo in model foods and model body fluids. Encapsulation enables long-term stabilization of biologically active compounds as well as posibility of their transport and controlled releasing in gastrointestinal tract. Encapsulation of probiotic bacteria could preserve their viability and long-term survival until the product expiration date. Thus, encapsulation is one of the most promissing procedures for production of foods and food suplements of great quality and high additional value.