Qualidade do leite bovino das propriedades produtoras de leite e das indústrias do Vale do Taquari-RS
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Data
2023-01
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Orientador
Rempel, Claudete
Banca
Cyrne, Carlos Candido Da Silva
Castro, Luís César De
Caon, Suhelen
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A região do Vale do Taquari é uma das principais produtoras de leite do Rio Grande do Sul. A qualidade do leite produzido pode ser influenciada por diversos fatores associados ao manejo, obtenção, transporte ou armazenamento do leite. A presente tese teve como objetivo avaliar a qualidade do leite cru refrigerado coletado nas propriedades produtoras de leite dos municípios do Vale do Taquari – RS, e dos leites cru refrigerado, pasteurizado e esterilizado pelo processo Ultra Hight Temperature (UHT) de indústrias dessa mesma região. Foram realizadas análises microbiológicas: contagem bacteriana total (CBT), contagem de mesófilos, contagem de psicrotróficos e análises de coliformes totais e termotolerantes. Análises físico-químicas e de composição do leite: acidez, densidade relativa, temperatura, proteína, gordura, lactose, extrato seco total (EST) ou sólidos totais (ST) e extrato seco desengordurado (ESD) ou sólidos não-gordurosos (SNG), para os três tipos de leite. Adicionalmente, no leite cru refrigerado das propriedades e dos caminhões tanque das indústrias realizou-se a contagem de células somáticas (CCS) e o teste de álcool alizarol. Foi realizada também a análise do microbiota, por meio do sequenciamento de alto rendimento do gene ribossomal 16S para os leites cru refrigerado, pasteurizado e esterilizado das indústrias. Os dados obtidos nas análises foram comparados com o que preceitua a legislação vigente, Instrução Normativa no 76 e Instrução Normativa n° 77 e com a Portaria n° 370, do Ministério da Agricultura, Pecuária e Abastecimento (MAPA). As coletas das amostras ocorreram em 33 propriedades produtoras de leite e duas indústrias beneficiadoras da região. Os resultados mostraram que há uma grande diversidade de gêneros e espécies, sendo que a indústria 1 demonstrou maiores quantidades de microrganismos. Os resultados das análises físico-químicas demonstraram que apenas duas propriedades estavam com a acidez acima do limite estabelecido pela legislação vigente. A indústria 1 apresentou acidez acima do limite nos três tipos de leite, alizarol positivo no leite cru refrigerado e densidade fora do estabelecido para o leite pasteurizado. Os parâmetros de composição do leite demostraram que mais da metade das propriedades (53%) e as duas indústrias estavam com a CCS acima do estabelecido. As análises microbiológicas demostraram CBT acima do permitido na indústria 1 e em nove das 33 propriedades analisadas. A quantidade de microrganismos psicrotróficos foi maior nas indústrias em comparação com as propriedades e ficou acima do estabelecido por autores da área. O leite cru refrigerado das indústrias apresentou maiores quantidades de CBT, psicrotróficos e coliformes totais e termotolerantes do que o leite cru refrigerado das propriedades produtoras de leite. A indústria 1 apresentou maiores quantidade de CCS, CBT, mesófilos e psicrotróficos que a indústria 2. Os parâmetros físico-químicos e microbiológicos são extremamente importantes para comprovar a qualidade do leite produzido e rastrear possíveis falhas no processamento. A utilização de ferramentas moleculares, como o sequenciamento de alto rendimento, torna o diagnóstico da qualidade do leite mais eficiente e minucioso, podendo ainda ser utilizado para a melhoria do processo produtivo.
The Vale do Taquari region is one of the main milk producers in Rio Grande do Sul. The quality of the milk produced can be influenced by several factors associated with handling, obtaining, transporting or storing the milk. This thesis aimed to evaluate the quality of refrigerated raw milk collected in milk producing properties in the municipalities of Vale do Taquari - RS, and of refrigerated, pasteurized and sterilized raw milk by the Ultra High Temperature (UHT) process from industries in the same region.Microbiological analyzes were carried out: total bacterial count (TBC), mesophilic count, psychrotrophic count and analysis of total and thermotolerant coliforms. Physical-chemical and composition analysis of milk: acidity, relative density, temperature, protein, fat, lactose, total dry extract (EST) or total solids (ST) and defatted dry extract (ESD) or non-fat solids (SNG), for the three types of milk. Additionally, the somatic cell count (SCC) and the alizarol alcohol test were performed on refrigerated raw milk from farms and from tank trucks. Microbiota analysis was also carried out, through high-throughput sequencing of the 16S ribosomal gene for refrigerated, pasteurized and sterilized raw milk from industries. The data obtained in the analyzes were compared with the provisions of current legislation, Normative Instruction No. 76 and Normative Instruction No. 77 and with Ordinance No. 370, of the Ministry of Agriculture, Livestock and Supply (MAPA). Samples were collected from 33 milk producing properties and two processing industries in the region. The results showed that there is a great diversity of genera and species, and industry 1 showed greater amounts of microorganisms. The results of the physical-chemical analyzes showed that only two properties had acidity above the limit established by current legislation. Industry 1 had acidity above the limit in the three types of milk, positive alizarol in refrigerated raw milk and density outside the established range for pasteurized milk. The milk composition parameters showed that more than half of the properties (53%) and the two industries had the CCS above the established. Microbiological analyzes showed CBT above the permitted level in industry 1 and in nine of the 33 properties analyzed. The amount of psychrotrophic microorganisms was higher in the industries compared to the properties and was above the established by authors in the area. Raw refrigerated milk from industries showed higher amounts of CBT, psychrotrophs and total and thermotolerant coliforms than raw refrigerated milk from dairy farms. Industry 1 had higher amounts of CCS, CBT, mesophiles and psychrotrophs than industry 2. The physical-chemical and microbiological parameters are extremely important to prove the quality of the milk produced and to track possible failures in processing. The use of molecular tools, such as high-throughput sequencing, makes the diagnosis of milk quality more efficient and thorough, and can also be used to improve the production process.
The Vale do Taquari region is one of the main milk producers in Rio Grande do Sul. The quality of the milk produced can be influenced by several factors associated with handling, obtaining, transporting or storing the milk. This thesis aimed to evaluate the quality of refrigerated raw milk collected in milk producing properties in the municipalities of Vale do Taquari - RS, and of refrigerated, pasteurized and sterilized raw milk by the Ultra High Temperature (UHT) process from industries in the same region.Microbiological analyzes were carried out: total bacterial count (TBC), mesophilic count, psychrotrophic count and analysis of total and thermotolerant coliforms. Physical-chemical and composition analysis of milk: acidity, relative density, temperature, protein, fat, lactose, total dry extract (EST) or total solids (ST) and defatted dry extract (ESD) or non-fat solids (SNG), for the three types of milk. Additionally, the somatic cell count (SCC) and the alizarol alcohol test were performed on refrigerated raw milk from farms and from tank trucks. Microbiota analysis was also carried out, through high-throughput sequencing of the 16S ribosomal gene for refrigerated, pasteurized and sterilized raw milk from industries. The data obtained in the analyzes were compared with the provisions of current legislation, Normative Instruction No. 76 and Normative Instruction No. 77 and with Ordinance No. 370, of the Ministry of Agriculture, Livestock and Supply (MAPA). Samples were collected from 33 milk producing properties and two processing industries in the region. The results showed that there is a great diversity of genera and species, and industry 1 showed greater amounts of microorganisms. The results of the physical-chemical analyzes showed that only two properties had acidity above the limit established by current legislation. Industry 1 had acidity above the limit in the three types of milk, positive alizarol in refrigerated raw milk and density outside the established range for pasteurized milk. The milk composition parameters showed that more than half of the properties (53%) and the two industries had the CCS above the established. Microbiological analyzes showed CBT above the permitted level in industry 1 and in nine of the 33 properties analyzed. The amount of psychrotrophic microorganisms was higher in the industries compared to the properties and was above the established by authors in the area. Raw refrigerated milk from industries showed higher amounts of CBT, psychrotrophs and total and thermotolerant coliforms than raw refrigerated milk from dairy farms. Industry 1 had higher amounts of CCS, CBT, mesophiles and psychrotrophs than industry 2. The physical-chemical and microbiological parameters are extremely important to prove the quality of the milk produced and to track possible failures in processing. The use of molecular tools, such as high-throughput sequencing, makes the diagnosis of milk quality more efficient and thorough, and can also be used to improve the production process.
Descrição
Palavras-chave
Coliformes; Mesófilos; Psicrotróficos; Análises físico-químicas; Microbiota do leite; Composição do leite; Coliforms; Mesophiles; Psychrotrophs; Physicochemical analysis; Microbiota; Milk composition
Citação
MÜLLER, Thais. Qualidade do leite bovino das propriedades produtoras de leite e das indústrias do Vale do Taquari-RS. 2023. Tese (Doutorado) – Curso de Ambiente e Desenvolvimento, Universidade do Vale do Taquari - Univates, Lajeado, 24 jan. 2023. Disponível em: http://hdl.handle.net/10737/3491.