O presente trabalho objetivou avaliar o efeito da gordura do leite caprino na resistência térmica do Mycobacterium fortuitum. A realização desta pesquisa é motivada pelos seguintes fatos: 1. a pasteurização lenta é amplamente utilizada para o beneficiamento do leite caprino destinado ao consumo e industrialização; 2. o binômio tempo x temperatura foi estabelecido com base na resistência térmica do Mycobacterium ssp; 3. o valor D expressa o tempo que se leva, a uma dada temperatura, para se reduzir um ciclo logarítmico de um microrganismo; 4. a gordura exerce efeito protetor sobre os microrganismos; 5. M. fortuitum é a espécie recomendada para testes iniciais, por ser menos patogênica e de crescimento rápido. Foram realizados dois experimentos (um com leite integral e outro com leite desnatado, com três repetições cada), utilizando-se amostras de cabras sadias. As amostras foram contaminadas com inóculo previamente padronizado e distribuídas em oito tubos com tampa, que foram submetidos a tratamento térmico em banho-maria à 65oC. Realizou-se a contagem das UFC/mL do leite contaminado antes do tratamento térmico (controle da contaminação) e dos tubos retirados nos tempos 0, 5, 10, 15, 20, 25 e 30 minutos. Realizou-se a diluição seriada até 10-7, com posterior semeadura em duplicata em placas de petri com meio Lowenstein-Jensen, incubadas por cinco dias à oC. Os resultados, em logarítmo, foram plotados em diagrama de dispersão, com posterior regressão linear para construção da curva de sobreviventes (ou curva de morte térmica), o valor D65oC foi calculado a partir da equação da reta obtida em cada repetição, e também a melhor curva obtida a partir das três repetições. Através dos resultados obtidos no presente trabalho obteve-se o valor D65oC do Mycobacterium fortuitum em leite caprino integral de 10,2 minutos e 8,61 minutos para o leite desnatado. Isso mostra que, na condição estudada a pasteurização lenta é capaz de reduzir 3,48 log de M. fortuitum em leite desnatado, e apenas 2,94 log em leite integral e, portanto, resultará em diferentes níveis de segurança ao consumidor. A variação nos valores D65oC observadas neste trabalho sugerem que a gordura não é a única responsável por essa diferença, pois houve variação entre as repetições realizadas no mesmo substrato. A variação entre os resultados em leite integral pode ser atribuída, pelo menos em parte, à composição da gordura que têm influência na resistência térmica dos microrganismos. A gordura do leite interfere negativamente na eficiência da pasteurização lenta sobre destruição de M. fortuitum. A importância dessa informação para a saúde pública é dependente, em primeiro lugar, da comprovação de que esse fenômeno é comum às espécies patogênicas de micobactérias, e determinar sua intensidade. A gordura não interfere no padrão de morte térmica no leite de cabra. / This work describes the results obtained to evaluate the effect of fat goat milk on thermal resistance of Mycobacterium fortuitum. This research is motivated for the following motives: 1. The holder pasteurization is extensive method using for the processing goat milk destined for consumption and industrialization; 2. The couple time x temperature was established for the thermal resistance of Mycobacterium ssp; 3. The value D express the necessary time, in a given temperature, to reduce a logarithmic cycle of microorganism; 4. The fat causes a protecting effect on the microorganisms; 5. Mycobacterium fortuitum is the specie recommended for beginnings tests, because it is less pathogenic and have fast growth. Two experiments were done (one using raw goat milk and another using skim goat milk, with three repetition each). The samples were contaminated with previous standard inoculum and distributed in eight tubes, that had been submitted a thermal treatment in water-bath in 65°C. The cfu/mL were counted in the contamined milk before the thermal treatment (contamination control) and the tubes pulled off in the times: 0, 5, 10, 15, 20, 25 e 30 minutes. Following was realized a series diluted until 10-7, with later spreaded in duplicate petri plates with medium Lowestein Jensen, incubated for five days in 37°C. The results obtained were represented in a logarithmic graph of dispersion diagram, with posterior linear regression for the construction survivor?s curve (or death thermal curve), the value D65oC was calculated from the equation of the straight line obtained in each repetition, and the best straight line obtained from the three repetitions too. Through the results obtained in the present work get a value D65oC of Mycobacterium fortuitum in raw goat milk the 10,2 minutes, and 8,61 minutes for skim goat milk, this mean that in these study conditions, the holder pasteurization is able to reduce 3,48 log of Mycobacterium fortuitum in skim milk and only 2,94 log in raw milk, and thus results in different security levels for the consumers. The variation observed in the values D65oC obtained in this work suggest that the fat doesn?t a unique responsible for this difference, because have a variation among the repetitions done in the same substrate. The variation between the results in raw milk can be attribute, in part, for the composition of fat that have a influence on the thermal resistance in the microorganisms. The fat milk interferes negatively in the holder pasteurization effective about the Mycobacterium fortuitum destruction. The importance on this information for the public health is dependent, in first moment, the proved that this phenomenon is common for the micobacteria pathogenic species, and determined its intensity. The fat doesn't interfere in the standard thermal death in the goat milk.

Made available in DSpace on 2016-05-02T13:55:30Z (GMT). No. of bitstreams: 1 PolianadeOliveiraCoelho-Dissertacao.pdf: 591748 bytes, checksum: 0ee9a76f737829a2f58b8fd626dbacca (MD5) Previous issue date: 2010-09-17 / Aflatoxins are hepatotoxic, immunosuppressive, mutagenic, carcinogenic and teratogenic metabolites produced by Aspergillus flavus and Aspergillus parasiticus. They are found in various kinds of food, especially grains, and are widely used in the manufacture of animal feed. Aflatoxin B1 has the highest toxic power, and its most important metabolite, aflatoxin M1, is eliminated mainly via the milk. The limit values of aflatoxin accepted by Brazilian legislation are 50 ppb for animal feed, and 0.5 µg/L and 5.0 µg/L, for liquid and powdered milk, respectively. Young people are great milk consumers, and thereby milk toxicity becomes an important public health issue. This study evaluated the fungal microbiota and incidence of aflatoxin M1 in the milk of goats raised in three farms, located in the south of Minas Gerais and Mogiana Paulista region. The culture medium Rose-Bengal Sabouraud agar was used to evaluate food fungal microbiota. The presence of aflatoxin B1 was assessed by thin layer chromatography. Aflatoxin M1 in milk was determined by immunoaffinity column cleanout with high performance liquid chromatography (HPLC). In addition, meteorological conditions were surveyed in the regions studied to measure the pluviometric index, the average temperature and relative humidity of air, where the periods of higher incidence of fungi and toxins were found in feed and milk. Two feed samples were collected: concentrate and fodder, with four replications, in two different seasons (rains and drought). Milk samples were also collected, with four replications. Two experiments were conducted: one in the rainy season; another in drought. Their statistical design was completely randomized and factorial . The Tukey test was applied at the 5% significance level. The results showed that the improved methods were efficient to detect aflatoxin: thin layer chromatography, in feed; and high performance liquid chromatography, in milk. The good quality of the goat milk was confirmed by the absence of aflatoxin in the samples. However, the qualitative analysis of Aspergillus cultures revealed that of the 64 samples analyzed, 22,6% were contaminated by aflatoxin B1. / As aflatoxinas são metabólitos tóxicos produzidos por Aspergillus flavus e Aspergillus parasiticus com efeitos hepatotóxicos, imunossupressores, mutagênicos, carcinogênicos e teratogênicos. Estão presentes em vários alimentos, principalmente nos grãos, sendo amplamente utilizados na fabricação de rações animais. A aflatoxina B1 é a de maior poder tóxico e o seu metabólito é eliminado principalmente no leite, sendo o de maior importância a aflatoxina M1. Os limites aceitos pela legislação brasileira são de 50 ppb de aflatoxinas para alimentos destinados a animais e de 0,5 µg/L e 5,0 µg/L de aflatoxina M1 para leite fluido e em pó, respectivamente. Devido à sua toxicidade, principalmente em indivíduos mais jovens, que são os maiores consumidores de leite, tornam-se um importante problema de saúde pública. Os objetivos deste trabalho foram avaliar a microbiota fúngica e a incidência de aflatoxina B1 em alimentos consumidos por cabras e a incidência de aflatoxina M1 em leite de cabras criadas em 3 propriedades localizadas na região do Sul de Minas Gerais e Média Mogiana Paulista. Os alimentos foram avaliados quanto à microbiota fúngica utilizando-se Ágar Sabouraud Rosa de Bengala. A detecção de aflatoxinas B1 foi avaliada pela técnica de cromatografia em camada delgada, enquanto, no leite, primeiramente foi feita a extração e purificação em colunas de imunoafinidade, sendo a detecção de aflatoxina M1 avaliada utilizando-se a cromatografia líquida de alta eficiência (HPLC). Aliado a estes levantamentos, foi realizada uma análise das condições meteorológicas das regiões de Minas Gerais e São Paulo, aferindo-se o índice pluviométrico, a temperatura média e a umidade relativa do ar onde foram verificadas e comparadas as épocas de maior incidência de fungos e suas toxinas nos alimentos e no leite. Foram colhidas amostras de dois alimentos (concentrado e volumoso) com quatro repetições e em duas épocas diferentes (chuva e seca) e amostras de leite também com quatro repetições em cada época. O delineamento estatístico foi inteiramente casualizado (DIC) em esquema fatorial e foi utilizado o teste Tukey com 5% de nível de significância. Os resultados obtidos revelaram que a otimização das referidas metodologias de cromatografia em camada delgada para análise de aflatoxina em rações e de HPLC no leite caprino mostraram-se eficientes. Em todas as amostras de leite caprino, não foi detectada a presença de aflatoxinas, demonstrando a boa qualidade do leite quanto à contaminação por essas toxinas. Porém, após a análise qualitativa da toxigenicidade das culturas da espécie do gênero Aspergillus, observou-se que, das 64 amostras de rações analisadas, 22,6 % encontravam-se contaminadas com aflatoxina B1.

Goat milk is primarily destined for the production of fermented products, in particular cheese. Therefore, the control of antibiotic residues in milk is of great importance, since these could have negative repercussions on technological properties of the milk as well as on the health of consumers. In milk quality control programs, microbial inhibitor tests are widely applied to detect antibiotics during the screening stage. However, tests are non-specific and may be affected by substances other than antimicrobials which could inhibit the growth of the test micro-organism, causing false positive results. The aim of this thesis was to evaluate the interference, related to the presence of different contaminants in goat milk, on the response of microbial inhibitor tests commonly used in Spain to detect antibiotics (BRT MRL, Delvotest SP-NT MCS and Eclipse 100 tests). The influence of the physicochemical characteristics of goat milk on the false positive outcomes in microbial screening tests was also investigated. The suitability of microbial inhibitor tests for screening antibiotics in colostrum secretions was studied by analysing antibiotic-free colostrum and milk samples from forty-three Murciano-Granadina goats, collected every 12 hours during the first week post-partum. Microbial inhibitor tests were not suitable for the analysis of goat colostrum because they presented a high percentage of doubtful and positive results (up 37.2% in the 36 hours after partum). To evaluate the effect of caprine colostrum on the microbial test response, antimicrobial-free goat milk spiked with different concentrations of colostrum was analysed to calculate the inhibitory concentrations producing 5% of positive results. The highest interferences were obtained for the addition of colostrum from 12 to 24 hours post-partum and the colostrum concentrations producing 5% positive results were between 5.1 and 34.6%. The BRT MRL was the test the most affected. In another study, the interference of detergents and disinfectants used for the cleaning of milking equipment and milk storage tanks of dairy farms was investigated. Antimicrobial-free goat milk was spiked with eight concentrations of different cleaning products (5 acid, 5 alkaline, 5 domestic washing-up liquids, and 1 disinfectant) and analysed using microbial screening tests. The presence of acid detergent and disinfectant based on sodium hypochlorite in goat milk did not affect the microbial test response. However, alkaline detergents at concentrations ≥ 1 ml/l could lead to false positive results in microbial inhibitor tests (up to 16.7%) and from 4 ml/l on 100% positive results were obtained. Regarding the products used for home use, and those used on farms and small size dairies, washing-up liquid containing sodium laureth sulphate and ethanol had the greatest effects on microbial inhibitor tests, even starting from a relatively low concentration (1 ml/l). On the other hand, the presence of a relatively low concentration of detergents in goat milk (0.5 ml/l) slightly modified the detection capability of the microbial inhibitor tests for amoxicillin, ampicillin, benzylpenicillin, and cloxacillin, although the detection of these drugs at MRL (safe level) was not compromised. Antiparasitic agent residues in goat milk could be another possible cause of false positive results in microbial screening tests. An in vitro study to evaluate the effect of seven parasiticides commonly used in dairy goats was carried out. Further two studies, where albendazole and ivermectin were applied to two groups of dairy goats in lactation were performed. It should be noted that the parasiticide ivermectin is banned for the treatment of animals producing milk for human consumption, although its inclusion in this study was considered interesting to understand the potential effect of their residues in milk, in the event the practice was performed illegally. In the in vitro study, raw antibiotic-free milk from goats was spiked individually with eight different concentrations of albendazole, closantel, diclazuril, febendazole, levamisole, diazinon, and ivermectin. The microbial inhibitor test results showed a great variability according to the test and the drug under study. Of the tests considered, the BRT MRL test was the most sensitive to antiparasitic agents, with the lowest concentrations of antiparasitic agent causing 5, 10, and 50% of positive results. Generally, closantel and diazinon were the antiparasitic agents that produced higher interferences in all tests, since low concentrations already resulted in positive results, while only higher concentrations of diclazuril and ivermectin showed an inhibitory effect. To evaluate the effect of albendazole residues on the microbial inhibitor test response, eighteen healthy Murciano-Granadina goats in mid-lactation were treated with a single oral administration of the commercially available albendazole registered for dairy sheep (7.5 mg/kg b.w. of active compound) with a withdrawal period of 4 days for milk production in ovine. Albendazole and its metabolite residues in goat milk after under cascade treatment were not detected above MRL from the third day post-administration. However, a high occurrence of non-compliant results was obtained for the BRT MRL test during the first six days after treatment, suggesting that factors related to the albendazole application other than the drug concentration are able to affect the microbial inhibitor test response in some cases. Regarding the ivermectin study, twenty-eight Murciano-Granadina goats infested with Sarcoptes scabiei var. caprae were treated with a subcutaneous injection of ivermectin (200 μg/kg b.w.), with a second dose applied seven days after the first treatment. Drug residues in goat milk were recorded during the first fifteen days of the experiment with concentrations ranging from 8.13 to 24.25 ng/ml. In addition, all the microbial screening tests seem to be affected by the ivermectin treatment, with BRT MRL the most affected (20%) compared with Delvotest SP-NT MCS and Eclipse 100 (6.6 and 5.7%, respectively). These positive results cannot be associated with the ivermectin concentration in goat milk, as the concentrations measured were lower than the inhibitory concentrations as reported in a previous in vitro study for these microbial tests. Thus, as suggested by some authors, interferences could be related to changes or alterations caused by the application of the parasiticide agent or by the parasitic disease itself, which could affect the immune response of the animals favouring the presence of inhibitory substances in milk. The study of the effect of the goat milk composition on the specificity (rate of false positive results) of microbial inhibitor tests for screening antibiotics was also considered. Thus, individual goat milk samples (n=200) were analysed by microbial inhibitor tests using both visual and instrumental classification of the test results. The highest specificity values were obtained for the instrumental interpretation of the test results (94-99% vs 90-96%) due to the occurrence of samples with intermediate colorations (green-yellow, yellow-blue) making the visual classification more difficult and subjective. A relation was found between positive results in BRT MRL and Eclipse 100 tests and an elevated fat content in the goat milk. Positive outcomes in Eclipse 100 were associated with the butyric acid concentration in the milk. Further, the Delvotest SP-NT MCS test response was affected by elevated pH values, high lactoferrrin and myristoleic acid concentrations in the goat milk. This percentage of positive results could be minimized by a pre-treatment prior to microbial inhibitor test analysis, such as fat removal by centrifugation (3,100 g for 10 min at 4 ºC) and/or heating (80 ºC for 10 min). Undoubtedly, improvements on the specificity of the microbial inhibitor tests for screening antibiotics in goat milk are desirable to avoid the destruction of milk compliant for human due to the occurrence of false positive results. The related financial losses affect farmers and dairies. However, it should be noted that the presence of contaminants in goat milk could be avoided by applying good farming practices designed to ensure that milk is obtained from healthy animals under proper hygienic conditions so ensuring the food safety of goat milk and related dairy products. / Romero Rueda, T. (2015). Evaluation of false positive results in microbial inhibitor tests for screening antibiotics in goat milk [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/48552 / TESIS

Tesis por compendio / [ES] Los residuos de antibióticos en la leche constituyen un aspecto de gran importancia para la salud pública y pueden tener un efecto negativo en la industria láctea. Para proteger al consumidor se han establecido los Límites Máximos de Residuos (LMR) para diferentes antibióticos en la leche cruda. Sin embargo, la transferencia de estas sustancias de la leche al queso ha sido poco estudiada y, por lo tanto, se desconoce el impacto de la presencia de antibióticos sobre el proceso de elaboración y la seguridad del queso. El objetivo de la tesis ha sido evaluar la transferencia de los antibióticos más empleados en el ganado caprino lechero, desde la leche a quesos curados y frescos, así como estudiar el efecto sobre el proceso de fabricación y la calidad de los quesos durante la maduración. Para alcanzar el objetivo se han realizado elaboraciones de quesos curados (60 días) a partir de leche en presencia de diversos antibióticos (amoxicilina, bencilpenicilina, cloxacilina, eritromicina, ciprofloxacina, enrofloxacina y oxitetraciclina) a niveles admisibles (LMR) y fabricaciones de leche libre de antibiótico como referencia. Los resultados obtenidos sugieren que la mayor parte de los antibióticos en la leche no afectaron al proceso de fabricación del queso. Solamente la eritromicina y oxitetraciclina incrementaron el tiempo requerido en el proceso de elaboración. Respecto a las características del queso evaluadas a diferentes tiempos de maduración (0, 30 y 60 días), las pocas diferencias encontradas se refirieron a la concentración de ácidos grasos libres, el color y las propiedades de textura, pero en su mayoría no fueron detectadas en la evaluación sensorial. Sin embargo, cantidades variables de antibióticos, se transfirieron de la leche al queso (entre 7,4 y 68%). Las quinolonas y oxitetraciclina presentaron las más elevadas tasas de retención, así como persistencia a lo largo de la maduración, con altas concentraciones de quinolonas (enrofloxacina: 148±12 µg/kg; ciprofloxacina: 253±24 µg/kg) y de oxitetraciclina (20±5,7 µg/kg) después de los 60 días de curado. En el estudio de quesos frescos, se evaluó la presencia de residuos de medicamentos en la leche pasteurizada y en los quesos frescos a partir de leche de cabra con antibióticos (amoxicilina, bencilpenicilina, cloxacilina, neomicina, eritromicina, ciprofloxacina, enrofloxacina y oxitetraciclina) a niveles de seguridad (LMR). Los resultados mostraron que altas cantidades de antibióticos, entre el 71 y el 100% de la concentración inicial en la leche cruda, permanecieron en la leche pasteurizada y que fueron transferidas al queso en gran medida, con porcentajes de retención que oscilaron entre 37,5 y 75%. Con respecto a los márgenes de seguridad de estos productos, se calcularon teniendo en cuenta diferentes grupos de edades (niños, adolescentes y adultos), y los efectos negativos de estos antibióticos sobre la salud. Los resultados indicaron que el mínimo margen de seguridad en la leche pasteurizada lo presentaron la ciprofloxacina, enrofloxacina, y eritromicina para el grupo de niños. En relación al queso fresco, se obtuvo un elevado margen de seguridad para todos los antibióticos y grupos de edad considerados, lo que sugiere que este producto probablemente no tenga efectos negativos en la salud del consumidor. Es importante enfatizar que concentraciones relativamente altas de antibióticos podrían permanecer en la leche de cabra pasteurizada y productos relacionados, como los quesos frescos y de corta maduración. La presencia de estos antibióticos podría contribuir al desarrollo y propagación de la resistencia a los antimicrobianos que actualmente constituye un grave problema a nivel mundial. Los resultados de este trabajo podrían servir a las autoridades de salud pública para evaluar si los sistemas actuales de control de antibióticos en la leche y los productos lácteos son adecuados o deberían ser revisados. / [CA] Els residus d'antibiòtics en la llet animal constitueixen un aspecte de gran importància per a la salut pública, i poden tindre un efecte negatiu en la indústria làctia. Per a protegir al consumidor s'han establit els Límits Màxims de Residus (LMR) per a diferents medicaments veterinaris en la llet crua. No obstant això, la transferència d'estes substàncies de la llet al formatge ha sigut poc estudiada i, per tant, es desconeix el impacte de la presència de antibiòtics sobre el procés d'elaboració i la seguretat del formatge. L'objectiu de la tesi ha sigut avaluar la transferència dels antibiòtics més empleats en el bestiar caprí lleter, des de la llet a formatges curats i frescos, així com l'efecte sobre el procés de fabricació i la qualitat dels formatges durant la maduració. Per a aconseguir l'objectiu s'han realitzat elaboracions de formatges curats (60 dies) a partir de llet en presència de diversos antibiòtics (amoxicilina, bencilpenicilina, cloxacilina, eritromicina, ciprofloxacina, enrofloxacina i oxitetraciclina) a nivells admissibles (LMR) i fabricacions de llet lliure d'antibiòtic (control) com a referència. Els resultats obtinguts suggerixen que la major part dels antibiòtics en la llet no van afectar el procés de fabricació del formatge. Només l'eritromicina i l'oxitetraciclina van incrementar el temps requerit en el procés d'elaboració del formatge. Respecte a les característiques del formatge avaluades a diferents temps de maduració (0, 30 i 60 dies), les poques diferències trobades es van referir a la concentració d'àcids greixos lliures, el color i les propietats de textura, però majoritàriament no van ser detectades en l'avaluació sensorial. No obstant això, quantitats variables d'antibiòtics, es van transferir de la llet al formatge (entre 7,4 i 68%). Les quinolones i l'oxitetraciclina van presentar les més elevades taxes de retenció, així com persistència al llarg de la maduració, amb altes concentracions de quinolones (enrofloxacina: 148±12 µg/kg; ciprofloxacina: 253±24 µg/kg) i d'oxitetraciclina (20±5,7 µg / kg) després dels 60 dies de curació. En l'estudi de formatges frescos, es va avaluar la presència de residus de medicaments en la llet pasteuritzada i en els formatges frescos a partir de llet de cabra amb antibiòtics (amoxicilina, bencilpenicilina, cloxacilina, neomicina, eritromicina, ciprofloxacina, enrofloxacina i oxitetraciclina) a nivells de seguretat (LMR). Els resultats van mostrar que altes quantitats d'antibiòtics, entre el 71 i el 100% de la concentració inicial en la llet crua, van romandre en la llet pasteuritzada i que van ser transferides al formatge en gran manera, amb percentatges de retenció que van oscil·lar entre 37,5 i 75%. Respecte als marges de seguretat d'estos productes, es van calcular tenint en compte diferent grups d'edats (xiquets, adolescents i adults), i els efectes negatius d'estos antibiòtics sobre la salut. Els resultats van indicar que el mínim marge en la llet pasteuritzada ho van presentar la ciprofloxacina, la enrofloxacina, i l'eritromicina per al grup de xiquets. En relació al formatge fresc, es va obtindre un elevat marge de seguretat per a tots els antibiòtics i grups d'edat considerats, la qual cosa suggereix que este producte probablement no tinga efectes negatius en la salut del consumidor. És important emfatitzar que concentracions relativament altes d'antibiòtics podrien romandre en la llet de cabra pasteuritzada i productes relacionats, com els formatges frescos i de curta maduració. La presència d'estos antibiòtics podria contribuir al desenrotllament i propagació de la resistència als antimicrobians que actualment constitueix un greu problema a nivell mundial. Els resultats d'este treball podrien servir les autoritats de salut pública per a avaluar si els sistemes actuals de control d'antibiòtics en la llet i els productes lactis són adequats o haurien de ser revisats. / [EN] Antibiotic residues in milk are a great concern for public health, and they have negative implications for the dairy industry. To guarantee the safety of milk and derivates, Maximum Residues Limits (MRL) for different veterinary drugs in raw milk have been established. However, the transfer of these substances from milk to cheese, has been poorly studied and, therefore, the impact of the use of raw milk containing antibiotics on the cheese-making and the cheese safety is thus far unknown. The aim of this thesis was to evaluate the transfer of the most widely used antibiotics used in dairy goats, from milk to matured and fresh cheese, as well as their effect on the cheese-making process and the quality characteristics of the cheeses during ripening. To this end, antibiotic-free milk was spiked individually with seven veterinary drugs (amoxicillin, benzylpenicillin, cloxacillin, erythromycin, ciprofloxacin, enrofloxacin and oxytetracycline) and used to make mature Tronchón cheeses, which were analyzed at different ripening times (0, 30, and 60 days) to determine antibiotic residues, pH, chemical composition, proteolytic and lipolytic activities, color, and textural properties. The cheese-making process was unaffected by the presence of most antibiotics in milk. Only erythromycin and oxytetracycline significantly increased the time required for cheese production. Regarding cheese characteristics, the few differences found were related to the free fatty acid concentration, color and textural properties, which remained mostly undetected by the sensory analysis panelists. However, variable amounts of antibiotics, ranging from 7.4 to 68 %, were transferred from milk spiked with antibiotics, to cheese. Oxytetracycline and quinolones presented the highest retention rates as well as persistence along maturation, with high concentrations of quinolones (enrofloxacin: 148±12 µg/kg, ciprofloxacin: 253±24 µg/kg) and oxytetracycline residues (20±5.7 µg/kg) in cheeses after 60 days of ripening. In the study of fresh cheeses was evaluated the presence of drug residues in pasteurized fluid milk and fresh cheeses obtained from goat milk containing antibiotics (amoxicillin, benzylpenicillin, cloxacillin, neomycin, erythromycin, ciprofloxacin, enrofloxacin and oxytetracycline) at safety levels (MRLs). The safety margin of these dairy products for consumers was also evaluated. Results showed that high amounts of antibiotics, between 71-100% of the initial concentration in raw milk, remained in pasteurized goat milk and were transferred to cheese to a high extent, with retention percentages ranging from 37.5 to 75%. Regarding the safety margin of goat milk products, calculated taking into account different age groups (children, teenagers and adults), and the published negative effects of such antibiotics on consumer health, results indicate that the minimum safety margin of pasteurized milk was obtained for ciprofloxacin, enrofloxacin and erythromycin in the group of children. Regarding fresh cheese, an elevated safety margin was obtained for all antibiotics and age groups considered. It is important to emphasize that relatively high concentrations of antibiotics could remain in pasteurized fluid goat milk and related products such as fresh cheese and cheeses of a short ripening period. The presence of these antibiotics in dairy products might contribute to the development and spread of antimicrobial resistance, which is considered an important public health concern worldwide. The result of this research could serve the public health authorities to assess if current control systems of antibiotics in milk and dairy products are adequate or have to be revised. / Por último, quiero dar las gracias a la educación pública que permite que la economía no sea una barrera para la formación y al “Programa de ayudas a la investigación” (FPI-2014) de la Universitat Politècnica de Valencia, que me concedió la oportunidad de realizar está investigación durante los 4 años de trabajo. / Quintanilla Vázquez, PG. (2019). Effect of antibiotics in goat milk on the manufacture and characteristics of cheese [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/125701 / TESIS / Compendio

No / This research work was carried out to compare the physicochemical parameters of milk samples from four different animal species namely cow, goat, camel and sheep. Milk samples were collected from different areas of Misurata, Libya and analyzed for the key physiochemical parameters, pH, titratable acidity, total solids, ash, fat, protein and lactose. Furthermore in this study the concentrations of Zinc (Zn), Cadmium (Cd), Chromium (Cr), Magnesium (Mg), Manganese (Mn), Potassium (K), Calcium (Ca) Copper (Cu), Iron (Fe) and Lead (Pb) in similar commercial milk specimens from the same area were determined using microwave plasma- atomic emission spectrometry In fresh cow’s milk, the mean concentrations of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K were 0.13± 0.19 (mg/l), 0.004± 0.001 (mg/l), 0.04± 0.01 (mg/l), 0.17± 0.11 (mg/l), 0.72± 0.02 (mg/l), 1.98± 0.04 (mg/l), 214.00± 0.20 (mg/l), 0.080± 0.05 (mg/l), 423.0± 3.5 (mg/l) and 427.0± 2.5 (mg/l), respectively. While the mean concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the goat’s milk were 0.761 ± 0.78 (mg/l), 0.085 ± 0.02 (mg/l), 1.253 ± 0.18 (mg/l), 0.400± 0.08 (mg/l), 1.23± 0.21 (mg/l), 3.110± 0.15 (mg/l), 140.0± 0.31 (mg/l), 0.097± 0.07 (mg/l), 473± 5.12 (mg/l) and 510± 6.05 (mg/l), respectively. The concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the camel’s milk were 0.025 ± 0.019 (mg/l), 0.091± 0.05 (mg/l), 0.069± 0.07 (mg/l), 0.080 ± 0.05 (mg/l), 1.680 ± 0.43 (mg/l), 5.380 ± 1.17 (mg/l), 120.0 ± 0.11 (mg/l), 0.094 ± 0.04 (mg/l), 520.0 ± 0.32 (mg/l) and 571.0± 0.81 (mg/l), respectively. The concentration of Pb, Cd, Cr, Cu, Fe, Zn, Mg, Mn, Ca and K, in the sheep’s milk were 0.062± 0.03, 0.106± 0.11, 0.040± 0.01, 0.201± 0.10, 0.880± 0.31, 5.350± 0.50, 180± 1.20, 0.072± 0.01, 478± 3.10, and 593.96± 1.87, respectively.

O valor nutricional e as características físico-químicas fazem com que os produtos lácteos caprinos sejam muito apreciados e tenham um alto valor agregado. Muitas bactérias láticas (BAL) possuem a capacidade de produzir compostos com propriedades benéficas à saúde, inclusive vitaminas do grupo B, como a riboflavina (B2) e o folato (B9), que participam de importantes funções metabólicas. O presente estudo objetivou isolar e identificar BAL capazes de produzir folato e riboflavina, utilizando leite de cabra cru e de queijos de cabra como fonte, para em seguida, avaliar a produção destas vitaminas em leite de cabra UHT, para estimar uma possível aplicação na produção de derivados lácteos de cabra com teores mais altos destas vitaminas. Um total de 179 isolados de BAL, sendo 87 provenientes de leite e 92 de queijos, foram obtidas e analisados quanto à produção de folato e de riboflavina extracelular (EC) e intracelular (IC), empregando-se ensaios microbiológicos apropriados. A produção de folato em meio de cultura a 37ºC foi observada em 151 isolados (84,4%) e de riboflavina em 15 isolados (8,4%), sendo que 14 produziram as duas vitaminas concomitantemente. A média da produção folato total (EC + IC) foi 138,8 µg/L, sendo que em 77 isolados (51%) a produção estava acima da média. Houve diferença significativa entre as médias de produção de folato total pelos isolados de leite e de queijo. A média da produção de riboflavina total (EC + IC) foi 363,7 µg/L, sendo que em 9 isolados (60%) a produção foi acima da média. Com base no RAPD-PCR e sequenciamento da porção 16S do rDNA, foram obtidos 19 perfis genéticos diferentes e identificadas 7 espécies, com predominância de Streptococcus thermophilus (7 isolados), Weissella paramensenteroides (6 isolados) e Lactococcus lactis subsp. lactis (4 isolados). Oito isolados produtores de folato acima da média foram selecionados e submetidos à avaliação da produção de folato em leite de cabra UHT a 37°C, sendo 7 positivas, com média da concentração de folato total de 120,55 µg/L, variando de 12,97 a 261,91 µg/L. Os melhores produtores de folato em leite de cabra UHT foram Lc. lactis subsp. lactis FP368 e St. thermophilus FP34v, FP170v e FP268v. A concentração de folato produzido por estes isolados foi acima da média, evidenciando seu interessante potencial de aplicação na produção de novos derivados lácteos caprinos com teores aumentados desta vitamina. Por outro lado, não foi possível detectar a produção de riboflavina em leite de cabra por nenhum dos isolados testados. / Due to the high nutritional value and physicochemical characteristics, goat milk and cheeses are highly appreciated. Many strains of lactic acid bacteria (LAB) are able to produce vitamins from the B complex, such as riboflavin (B2) and folate (B9). These vitamins have important metabolic roles. The present study aimed to isolate riboflavin- and folate-producing LAB strains from goat milk and cheeses, and evaluate the potential application of those strains in the production of goat dairy products with higher content of these vitamins. A total of 179 LAB isolates were obtained from milk (87) and cheese (92) samples. The isolates were evaluated for production of extra (EC) and intracellular (IC) riboflavin and folate, applying appropriate microbiological methods. Among these isolates, 151 (84.4%) were able to produce folate, while 15 (8.4%) displayed the ability to produce riboflavin, and 14 produced both vitamins. The average production of total folate (EC + IC) was 138.8 µg/L, and the amount of folates produced by 77 isolates (51%) were above this average. The differences observed for the average production of total folate from milk and cheese isolates were statistically significant. For total riboflavin (EC+ IC), the average rate was 363.7 µg/L. Nine isolates (60%) presented production rates above the average. No significant difference was observed between the average production of total riboflafin from milk or cheese isolates (319.3 µg/L and 379.8 µg/L, respectively). Based on RAPD-PCR and 16S rDNA sequencing, 19 different genetic profiles were obtained and 7 species were identified, with predominance of Streptococcus thermophilus (7 isolates), Weissella paramensenteroides (6 isolates), and Lactococcus lactis subsp. lactis (4 isolates). Eight isolates that produced folate above the average were selected and tested for vitamins production in UHT goat milk at 37°C. Seven isolates produced an average of 120.55 µg/L of folate in the milk and concentration varied from 12.97 to 261,91 µg/L. The best folate producers were Lactococcus lactis subsp. lactis FP368, Streptococcus thermophilus FP34v, Streptococcus thermophilus FP170v and Streptococcus thermophilus FP268v. The amount of folate produced by these isolates surpassed the average, and was above the amounts described in other studies, evidencing their potential application in the production of goat dairy products with higher content of folate. None of the tested isolates was able to produce riboflavin in UHT goat milk.

Changes occur in milk during the technological processing of raw milk, which also affect the properties of milk fat. Dairy products may have different properties compared to the raw milk. Chemical and microbial processes can alter the presence and distribution of individual fatty acids and thus influence the nutritional value of the product. The aim of this thesis was to assess the presence of fatty acids in milk fat of goat milk and to evaluate differences in the spectrum of fatty acids in goat milk and yoghurt produced from it.

ALVES, Layane Maciel. Iogurte caprino adicionado de prebiótico e geleia de manga: aspectos físico-químicos, microbiológicos e sensoriais. 2015. 85 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Tecnologia de Alimentos, Fortaleza-CE, 2015 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-07T12:44:49Z No. of bitstreams: 1 2015_dis_lmalves.pdf: 1349949 bytes, checksum: 167fa06f085997ece573fead2dc37a4a (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-07T12:45:07Z (GMT) No. of bitstreams: 1 2015_dis_lmalves.pdf: 1349949 bytes, checksum: 167fa06f085997ece573fead2dc37a4a (MD5) / Made available in DSpace on 2016-07-07T12:45:07Z (GMT). No. of bitstreams: 1 2015_dis_lmalves.pdf: 1349949 bytes, checksum: 167fa06f085997ece573fead2dc37a4a (MD5) Previous issue date: 2015 / The increasing search for healthy foods enables the development of products that provide benefits to consumer health. This study aimed to elaborate goat yogurt added prebiotic and mango jam, combining the therapeutic benefits and nutritional value of goat milk yogurt and mango to the functional properties of inulin. Inulin is a dietary fiber widely used in food both for its technological attributes as for its nutritional benefits. For product development, was used an experimental design type Rotational central composite design composed of eleven trials. By Response Surface Methodology (RSM), three goat yogurt formulations were selected with different concentrations of inulin and gelatin, taking as dependent variable the apparent viscosity parameter. The selected goat yogurt formulations (A: 3 % inulin and 0.5 % gelatin; B: 5 % of inulin and 0.45 % gelatin and C: 7 % inulin and 0.4 % gelatin), mango jam and raw materials (goat milk and mango) were submitted to physical, chemical and physico-chemical evaluations. The goat yogurt added prebiotic and mango jam were submitted to microbiological analyzes (count of fecal coliforms, molds and yeasts, total lactic acid bacteria, coagulase-positive staphylococci and Salmonella spp. determination) and sensory evaluation (acceptance tests, with respect to the attributes: appearance, color, aroma, flavor, texture and overall impression, using hedonic scale of 9 points; preference and purchase attitude tests). The results of all analyzes receive statistical treatment through the Analysis of Variance (ANOVA) and the means were compared using the Tukey test. According to the results, it was found that all manufactured products attended the required legal specifications. The sensory evaluation showed that the three formulations were well accepted for all attributes, with no significant difference (p>0,05) in the acceptance and preference of the samples, except for appearance. The three samples showed positive intention to purchase by potential consumers. The addition of different concentrations of inulin and gelatin allowed to obtain goat yogurt with similar consistency to bovine products found in the market. Therefore, this study enabled the development of a technological alternative to using raw materials produced in the Northeast region of Brazil, goat milk and mango, and the making available of an innovative dairy product in the market. / A busca crescente por alimentos saudáveis possibilita o desenvolvimento de produtos que tragam benefícios à saúde do consumidor. Este trabalho visou elaborar iogurte caprino adicionado de prebiótico e geleia de manga, aliando os benefícios terapêuticos e valores nutricionais do iogurte caprino e da manga às propriedades funcionais da inulina. A inulina é uma fibra alimentar amplamente utilizada em alimentos tanto por seus atributos tecnológicos quanto por seus benefícios nutricionais. Para o desenvolvimento do produto, foi utilizado o planejamento experimental do tipo DCCR (Delineamento Composto Central Rotacional) composto por onze ensaios. Por meio da Metodologia de Superfície de Resposta (MSR), foram selecionadas três formulações de iogurte caprino com diferentes concentrações de inulina e gelatina tendo como resposta o parâmetro de viscosidade aparente. As formulações de iogurte caprino selecionadas (A: 3 % de inulina e 0,5 % de gelatina; B: 5 % de inulina e 0,45 % de gelatina e C: 7 % de inulina e 0,4 % de gelatina), a geleia de manga e as matérias-primas (leite caprino e manga) foram submetidas a avaliações físicas, químicas e físico-químicas. O iogurte caprino adicionado de prebiótico e geleia de manga foi submetido a análises microbiológicas (contagem de coliformes termotolerantes; bolores e leveduras; bactérias láticas totais; estafilococos coagulase positiva e pesquisa de Salmonella spp.) e sensoriais (testes de aceitação, com relação aos atributos aparência, cor, aroma, sabor, consistência e impressão global, utilizando escala hedônica de 9 pontos; teste de preferência e de atitude de compra). Os resultados de todas as análises receberam tratamento estatístico por meio da Análise de Variância (ANOVA) e as médias foram comparadas pelo teste de Tukey. De acordo com os resultados obtidos, foi constatado que todos os produtos elaborados atenderam às especificações legais exigidas. A avaliação sensorial mostrou que as três formulações foram bem aceitas para todos os atributos avaliados, não havendo diferença significativa (p>0,05) na preferência e aceitação das amostras, exceto para a aparência. As três amostras apresentaram intenção de compra positiva pelos potenciais consumidores. A adição de diferentes concentrações de inulina e gelatina propiciou a obtenção de iogurte caprino com consistência similar aos iogurtes bovinos encontrados no mercado. Portanto, esta pesquisa proporcionou o desenvolvimento de uma alternativa tecnológica para utilização de matérias-primas produzidas na região Nordeste, leite caprino e manga, disponibilizando um produto lácteo inovador no mercado.

The aim of this diploma thesis is to asses the effect of various factors on the milk production and its content in regard to goat's milk in the years 2015 to 2017. The evaluation was conducted on goat farm Richmond Stars in Chotětov. The farm currently accommodates 31 goats of the white shorthaired breed. They are still opting for the one rectangular space solution. The feeds consist of bulk fodder, silage, hay and grass (pasture during summer). The feed composure is the same throughout the whole year. The water supply system consists of water containers with manual refill. The goats are divided into groups based on their age. Milking takes place twice a day. The data on milk production was processed using Microsoft Excel and Statistica. When comparing the overall milk productivity with the average of Czech Republic, there were statistically significant differences found in the fat content in the year 2016, in the protein content in years 2015, 2016 and 2017, in the lactose content in the year 2015. In all cases, the Richmond Stars farm was the one with better score. Other results were evaluated as inconclusive and therefore no statistically significant difference was found. When considering the impact of the goat's age on the milk productivity and the goat's milk content, there was a statistically conclusive impact in the productivity (milking) itself as well as in the fat content. When observing the impact of the father-line on the productivity level and the milk content, there was a statistically conclusive result only in the fat content. When evaluating the impact of the period of birth on the milk productivity and milk content, there was a statistically conclusive impact on the fat and lactose content. All other results, specifically the productivity (milking), were evaluated as inconclusive and therefore were not statistically significant for the purpose of evaluation of the milk productivity characteristics.

Submitted by Maike Costa (maiksebas@gmail.com) on 2017-02-13T13:53:31Z No. of bitstreams: 1 arquivototal.pdf: 3030584 bytes, checksum: 5b069ccf943f165754f6c7fca30071dc (MD5) / Made available in DSpace on 2017-02-13T13:53:31Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 3030584 bytes, checksum: 5b069ccf943f165754f6c7fca30071dc (MD5) Previous issue date: 2015-02-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Goat milk is a highly nutritious food that provides therapeutic and dietary characteristics, being an excellent source for deriving products that has functional potential, whose nutritional benefits can be improved by enriching them with probiotic strains. Milk and dairy products can provide nutritional support for patients with intestinal inflammation. Inflammatory Bowel Disease (IBD) is a debilitating and immunologically-mediated disease that leads to tissue destruction in the gastrointestinal tract, which comprises Crohn's disease (CD) and ulcerative colitis (UC). This study aimed at evaluating the intestinal anti-inflammatory effect of goat milk and goat yogurt with addition of Lactobacillus acidophilus, with or without native bee honey (Melipona scutellaris), in rats with induced colitis. In the experiment female wistar rats (190 a 240 g), were randomized in 7 groups (n = 10): Non-colitic; Colitic; Goat milk (GM); Goat yogurt (without honey) (GY); Goat yogurt with honey (10%) (GYH); Goat yogurt with honey (10%) twice a day (GYH/2x), and Sulfasalazine (250 mg/kg) (SAZ). The animals received 1 ml of the product via gavage during 14 days. After this period, colitis was induced with acetic acid (0.5 mL of 10% v/v in 0.9% saline). Forty eight hours after inducing the colitis, the animals were euthanized. Were assessed the macroscopic and microscopic damage of colitis, inflammatory parameters, expressed by myeloperoxidase (MPO), Tumor Necrosis Factor (TNF)-α, interleukin (IL)1-β, Cyclooxygenase (COX)-2 and Inducible Nitric Oxide Synthase (iNOS) and oxidative stress markers, such as malondialdehyde (MDA), and total glutathione. The pre-treatment with goat milk, goat yogurt or sulfasalazine resulted in a significant reduction of the macroscopic damage score (p <0.01 vs. colitic group), and improved the MPO activity (p <0.01 vs. colitic group), the levels of pro-inflammatory citokynes, TNF-α (p <0.01 vs. colitic group) (p <0.01 SAZ vs. LC, ICM e ICM/2x) and IL1-β (p <0.01 vs. colitic group). It also promoted a significant reduction in oxidative stress that could be observed by the reduction in the MDA (p <0,01 vs. colitic group) (p <0.05 LC vs. SAZ) and the increase in the glutathione (p <0.01 vs. colitic group) (p <0.01 SAZ vs. LC, IC e ICM/2x). The benefits of the pre-treatments were also demonstrated by the preservation of the colonic cytoarchitecture, and the decreased expression of the COX-2 (p <0.05 vs. colitic group) and the iNOS (p <0.05 vs. colitic group). In conclusion, it was observed that goat milk, goat yogurt and sulfasalazine exerted anti-inflammatory effect on colitis model induced by acetic acid in rats. Therefore, these goat dairy products may be a valuable alternatives to traditional medications and a potential functional food for the prevention of IBD. / O leite de cabra é um alimento de alto valor nutritivo que proporciona características terapêuticas e dietéticas, sendo assim uma excelente fonte para obtenção de produtos com potencial funcional, cujos benefícios nutricionais podem ser aprimorados enriquecendo-os com cepas probióticas. O leite e seus derivados podem prover o suporte nutricional necessário para pacientes com inflamação intestinal. A Doença Inflamatória Intestinal (DII) é uma doença imunologicamente mediada que leva à destruição do tecido no trato gastrointestinal e, compreende a Doença de Crohn (DC) e a Colite Ulcerativa (CU). O objetivo deste estudo foi avaliar o efeito anti-inflamatório intestinal do leite e do iogurte caprino adicionado de Lactobacillus acidophillus, acrescido ou não de mel de abelhas nativas (Melipona scutellaris), em ratas com colite induzida. Foram utilizadas ratas Wistar (190 a 240 g) divididas em 7 grupos experimentais (n = 10): Não colítico; Colítico; Leite de Cabra (LC); Iogurte Caprino (sem mel) (IC); Iogurte Caprino adicionado de Mel (10%) (ICM), Iogurte Caprino adicionado de Mel (10%) duas vezes ao dia (ICM/2x) e Sulfassalazina 250 mg/kg (SAZ). Os animais receberam, diariamente, via gavagem, 1 mL do produto durante 14 dias. Depois deste período, foi, então, induzida a colite com ácido acético (0,5 mL de 10% v/v em solução salina 0,9%). Quarenta e oito horas depois da indução, os animais foram eutanasiados. Foram avaliados o dano macroscópico e microscópico da colite, os parâmetros inflamatórios, expressos pela Mieloperoxidase (MPO), Fator de Necrose Tumoral (TNF)-α, Interleucina (IL)1-β, Cicloxigenase (COX)-2 e iNOS (Óxido Nítrico Sintetase Induzida) e os marcadores de estresse oxidativo, como o Malondialdeído (MDA) e glutationa total. O pré-tratamento com o leite, iogurte caprino ou sulfassalzina reduziu o escore do dano macroscópico (p <0,01 vs. colítico), e melhorou significativamente a atividade de MPO (p <0,01 vs. colítico), os níveis das citocinas pró-inflamatórias, TNF-α (p <0,01 vs. colítico) (p <0,01 SAZ vs. LC, ICM e ICM/2x) e IL1-β (p <0,01 vs. colítico). Também reduziu significativamente o estresse oxidativo, observado pela redução de MDA (p <0,01 vs. colítico) (p <0,05 LC vs. SAZ) e previniu a depleção de glutationa (p <0,01 vs. colítico) (p <0,01 SAZ vs. LC, IC e ICM/2x). Este efeito também foi demonstrado pela preservação da citoarquitetura colônica, e diminuição da expressão de COX-2 (p <0,05 vs. colítico) e iNOS (p <0,05 vs. colítico). Concluiu-se que o leite de cabra, o iogurte caprino e a sulfassalazina exerceram efeito anti-inflamatório no modelo de colite induzida por ácido acético em ratos. Portanto, estes produtos lácteos caprinos podem ser alternativas valiosas aos medicamentos tradicionais e um potencial alimento funcional para a prevenção da DII.