Portal de Pesquisa da BVS Veterinária

Tese em Português | VETTESES | ID: vtt-216211

Resumo

Capítulo 1: O estudo foi realizado com o objetivo de caracterizar e tipificar os Sistemas de Producao Leiteiros (SPL) e a ocorrencia de contaminacao por micotoxinas e aflatoxina M1 (AFM1) na regiao do Sisal da Bahia, identificando seus principais motivos e ocorrencia regional. Na primeira etapa foram estudados 111 SPL. Os produtores foram submetidos a uma entrevista semiestruturada e questionario guia aprovado, relativo a variaveis quantitativas e qualitativas. Foi utilizada a Analise Fatorial Multipla (AFM) seguida de Tipologia dos SPL. Foram realizadas analises qualitativas para AFM1 em todos os SPL. A segunda etapa teve inicio apos triagem, na qual 23 SPL foram acompanhados durante um ano e colhidas amostras de alimentos e leite de cabra para deteccao de micotoxinas e AFM1 no inverno e na primavera. Foi determinada a probabilidade de contaminacao por micotoxinas e AFM1 e as correlacoes entre a contaminacao delas dentro de cada Tipo. Foram colhidas amostras de leite para avaliacao fisico-quimica dos componentes em funcao dos Tipos de SPL utilizando AFM. Utilizou-se o Software R 2.15.0 e pacote Factor Miner em todas as analises. As dimensoes 1 e 2 foram caracterizadas pelas variaveis sociais e manejo sanitario, respectivamente. A partir da tipologia foram obtidos tres Tipos de SPL. Foram detectadas seis amostras positivas para micotoxinas (AF B1, B2, G2 e Zearalenona) em 8,22% (06/73) amostras de alimentos colhidos nos SPL selecionados. Houveram dois resultados positivos no inverno e quatro na primavera. Houveram tres amostras positivas para AFM1 (0,01 a 0,04 g/kg) e em nenhuma das amostras os niveis de concentracao excederam os limites maximos do Brasil (0,5 g/kg) e da Uniao Europeia (0,05 g/kg). Todos os casos positivos de contaminacao ocorreram no Tipo 3. O Tipo 3 apresentou 25% (p< 0,01) de probabilidade estimada para contaminacao por micotoxinas e 29% (p< 0,01) para AFM1 e os Tipos 1 e 2 apresentaram 0% (p> 0,01). A associacao bidirecional via correlacao demonstrou que a micotoxina teve correlacao de 85% com a AFM1 no teste de Kendall e de 88% no teste de Spermean. As comparacoes das probabilidades de contaminacao por micotoxinas e AFM1 entre os Tipos demonstraram que o Tipo 3 foi diferente (p<0,05) dos Tipos 1 e 2, e os Tipos 1 e 2 nao foram diferentes (p>0,05) entre si. As variaveis de qualidade do leite nao diferiram (p>0,05) entre os Tipos. Caracteristicas climaticas, de gestao (anotacoes zootecnicas, decisao e centralizacao), de manejo sanitario e alimentar, e o numero de atividades desenvolvidas no SPL diferenciam muito os produtores quanto a contaminacao. Houve contaminacao para micotoxinas e AFM1 nos SPL mais especializados em producao de leite (Tipo 3), porem nao apresentaram risco aos consumidores da regiao estudada em 2016. Capítulo 2: O objetivo deste estudo foi avaliar a composicao quimica, perfil proteico, rendimento do leite, composicao quimica e qualidade sensorial do queijo minas frescal produzido a partir do leite de diferentes genotipos de cabra sob o mesmo manejo dietetico. Foram utilizadas 23 cabras lactantes, recem-paridas, 9 da raca Saanen (PVI: 35,9 ± 1,3 kg), 8 da raca Moxoto (PVI: 25,9 ± 1,9 kg) e 6 da raca Anglo Nubiana (PVI: 42,6 ± 1,6 kg) com idade media de dois anos. As amostras de leite de diferentes grupos geneticos (GG) apresentaram os valores medios de gordura (3,66 6,79%), proteina (3,31 4,98%), lactose (4,27 4,47%), solidos totais (ST: 12,04 17,12%), extrato seco desengordurado (ESD: 8,84 10,33%), nitrogenio ureico (NU: 27,24 30,09%) e caseina (2,43 3,94%). Houve efeito (P<0,05) de GG para todos os componentes do leite avaliados. O periodo de lactacao influenciou (P<0,05) na producao de leite e nos teores de proteina, lactose, NU e caseina. Em relacao ao perfil proteico do leite, houve efeito (P <0,05) de GG sobre os teores de proteina bruta, nitrogenio nao-caseinoso, proteina verdadeira e caseina. Da mesma forma, foi verificado efeito (P<0,05) nas proporcoes de nitrogenio nao-proteico, nitrogenio nao-caseinoso, proteina verdadeira, caseina e proteina serica com base no teor de proteina total. Cabras Anglo Nubianas apresentaram valores intermediarios destes compostos em comparacao as cabras das racas Moxoto e a Saanen. Os valores medios da composicao do queijo de Minas frescal para materia seca (MS), umidade, cinzas (MS e umidade), EE (MS e umidade), proteina e rendimento (% e - L de leite/Kg de queijo) oscilaram entre 40,32 43,35%, 56,68 59,97%, 0,99 1,00%, 2,29 2,48%, 46,13 53,16%, 18,58 23,15%, 39,04 41,79%, 17,60 25,88% e 4,07 6,09%. Todas as variaveis de composicao do queijo apresentaram diferenca (P<0,05) durante o periodo de lactacao. Houve efeito (P<0,05) de interacao entre GG e periodo de lactacao para cinzas (MS%), EE (umidade%), proteina bruta e rendimentos (% e L de leite/Kg de queijo). Cabras Moxoto produziram leite de maior rendimento (%) em praticamente todos os periodos de lactacao. Houve efeito (P<0,05) de GG para textura na avaliacao sensorial do queijo de cabra. Queijos de Cabras Saanen apresentaram menor (P<0,05) nota quando comparados aos queijos de Anglo Nubiana e a Moxoto. Para os demais aspectos sensoriais avaliados: cor, odor, sabor, aceitacao global nao houve diferenca (P>0,05). O Indice de Aceitabilidade do queijo minas frescal apresentou percentuais de 86,63% (Moxoto), 86,07% (Anglo) e 84,55% (Saanen). Foi utilizada analise de componentes principais para buscar a discriminacao entre os GG no perfil sensorial de queijos. Houve separacao entre as amostras de acordo com a aproximacao das caracteristicas sensoriais entre os queijos das racas Anglo Nubiana e da Moxoto. Podemos concluir que os parametros fisico-quimicos do leite e do queijo de cabras foram diferentes de entre as racas estudadas. Cabras Moxoto apresentaram menor producao de leite, maior rendimento do leite e melhor perfil sensorial quando comparado as racas Saanen e Anglo Nubiana. A textura do queijo minas frescal e uma caracteristica sensorial influenciada pela raca das cabras.

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Chapter 1: The objective of this study was to characterize and typify Milk Production Systems (MPS) and the occurrence of contamination by mycotoxins and aflatoxin M1 (AFM1) in the Sisal Region of Bahia, identifying their main reasons, regional occurrence, and prevalence. In the first stage, 111 MPS were studied. The producers were submitted to a semi-structured interview and approved guide questionnaire following the methodologies described by Foody (2003) and Ramos (2008), regarding quantitative and qualitative variables. It was used a Multiple Factorial Analysis (MFA) followed by MPS Typology. Qualitative analyzes were performed for AFM1 in all MPS. The second stage started after the screening, in which 23 MPS were followed for one year and food and milk samples were collected for mycotoxins and AFM1 detection in the winter and spring. The probability of contamination by mycotoxins and AFM1 and the correlations between the contamination of them within each Type were determined. Milk samples were collected for physicochemical analysis of the components according to MPS Types using AFM. Software R 2.15.0 and Factor Miner package were used in all analyzes. Dimensions 1 and 2 were characterized by social variables and sanitary management, respectively. From the typology, three types of MPS were obtained. Six positive samples for mycotoxins (AF B1, B2, G2 and Zearalenone) were detected in 8.22% (06/73) samples of foods collected from the selected MPSs. There were two positive results in the winter and four in the spring seasons. There were three positive samples for AFM1 (0.01 to 0.04 g / kg) and, in none of the samples, did the concentration levels exceed the maximum Brazilian limits (0.5 g / kg) (BRASIL, 2011) and the European Union (EU) (0.05 g / kg). All positive cases of contamination occurred in Type 3. Type 3 presented 25% (P<0.01) of probability estimated for mycotoxin contamination and 29% (P<0.01) for AFM1 and, Types 1 and 2, presented 0% (P>0.01). Bidirectional association via correlation showed that mycotoxin had a correlation of 85% with AFM1 in the Kendall and 88% in the Spermean tests. Comparisons of probabilities of contamination by mycotoxins and AFM1 among Types showed that Type 3 was different (P<0.05) from Types 1 and 2, and Types 1 and 2 were not different (P>0.05) between them. The milk quality variables did not differ (P>0.05) between the types. Climatic characteristics, management (zootechnical notes, decision, and centralization), of sanitary and food management, and the number of activities developed in the MPS greatly differentiate producers from contamination. There was contamination for mycotoxins and AFM1 in more specialized MPS in milk production (Type 3); however, did not present risk to the consumers of the studied region in 2016. Chapter 2: The objective of this study was to evaluate the chemical composition, proteic profile, milk yield, chemical composition and sensorial quality of Minas frescal cheese produced from milk of different goat genotypes under the same dietary management. Twenty-nine lactating goats, 9 Saanen (IBW: 35.9 ± 1.3 kg), 8 Moxoto breed (IBW: 25.9 ± 1.9 kg) and 6 Anglo Nubian breed (IBW: 42.6 ± 1.6 kg) with mean average of two years. The milk samples from different genetic groups (GG) showed mean values of fat (3.66 - 6.79%), protein (3.31 - 4.98%), lactose (4.27 - 4.47%), total solids (TS: 12.04-17.12%), total dry extract (TDE: 8.84-10.33%), ureic nitrogen (UN: 27.24- 30.09%) and casein (2.43-3.94%). There was an effect (P <0,05) of goat genotypes for all milk components evaluated. There was effect of the lactation period (P<0,05) on milk yield and protein, lactose, UN and casein levels. In relation to the proteic profile of the milk, there was effect (P<0,05) of GG on the crude protein, non-casein nitrogen, true protein and casein contents. Likewise, there was effect (P<0,05) on the proportions of non-protein nitrogen, non-casein nitrogen, true protein, casein and serum protein based on the total protein content. Anglo Nubian goats presented intermediate values of these compounds in comparison to the goats from Moxoto and Saanen genotypes. The mean values of the composition of Minas frescal cheese for dry matter (DM), moisture, ash (DM and humidity), EE (DM and moisture), protein and yield (% and liters milk (L) / kg cheese) ranged from 40.32 - 43.35%, 56.68 - 59.97%, 0.99 - 1.00%, 2.29 - 2.48%, 46.13 - 53.16%, 18.58 - 23.15% 39.04 - 41.79%, 17.60 - 25.88% and 4.07 - 6.09%. All of the cheese composition variables showed a difference (P<0,05) during the lactation period. There was an interaction effect (P<0.05) between GG and lactation period for ash (DM %), EE (moisture %), crude protein and yields (% and L milk / kg cheese). Moxoto goats produced higher milk yield (%) in almost all lactation periods. There was an effect (P <0.05) of GG for texture in the sensory evaluation of goat cheese. Saanen goat cheese presented lower (P<0.05) grade when compared to Anglo Nubian and Moxoto cheeses. For the other sensorial aspects evaluated: color, odor, taste, overall acceptance there was no difference (P>0.05). The Acceptability Index of the Minas frescal cheese presented percentages of 86.63% (Moxoto), 86.07% (Anglo) and 84.55% (Saanen). Principal component analysis was used to search for discrimination between GG in the sensory profile of cheeses. The samples were separated according to the approximation of the sensorial characteristics between the cheeses of the Anglo Nubian and Moxoto breeds. It is concluded that the physical-chemical characteristics of milk and goat cheese were different from the studied breeds. Moxoto goats presented lower milk production, higher milk yield and better sensory profile when compared to the Saanen and Anglo Nubian breeds. The texture of the Minas frescal cheese is a sensorial characteristic influenced by the breed of goats.

Biblioteca responsável: BR68.1