Andrea Troller Pinto

Caracterização da mastite subclínica em caprinos produzidos em sistema orgânico no Rio Grande do Sul

Milk and derivates are recognized as vehicle of different pathogens for humans. These micoorganisms may manifest as post-milking contamination or as in infections in the animal itself, particularly in mastitis. The aim of present study was characterizes the occurrence of mastitis and management aspects in dairy-goats raised in three farms of organic milk. The correlation between mastitis and goat husbandry was also investigated. The clinical exam of the mammary glands of 64 dairy-goats did not reveal the presence of clinical mastitis. Nevertheless, the California Mastitis Test (CMT) identified 54 (22.7%) reactive mammary halves (+ or ++). From 238 milk samples collected, 37 (15.6%) were positive for bacterial isolates. Coincident positive results for bacterial isolate tests and CMT were observed in only eight samples, which indicate a sensitivity index of 21.6% for the caprine subclinical mastitis diagnosis test. Coagulase-negative staphylococci (CNS) were identified as the most frequent pathogen in milk samples (83.8%). The in vitro sensitivity test revealed CNS strains resistant to cotrimoxazole (50%), ampicillin (48.1%), nitrofurantoine (7.7%), cefaclor (7.14%), and oxacilline (3.85%). Cefalotine, gentamicin, neomycin, streptomycin, and tetracycline were the most effective drugs. No correlation was observed between the occurrence of subclinical mastitis and race, lactation period, drinking water quality in farms, or milking system as adopted in the present study.

Ensaios de penetração de Salmonella Enteritidis em ovos de galinha com diferentes qualidades de casca, submetidos ou não a lavagem industrial e a duas temperaturas de armazenagem

Estudou-se o comportamento da Salmonella Enteritidis quando em contato com a superficie de ovos de consumo, classificados de acordo com a qualidade da casca ou com tratamentos (lavados ou nao), usando fezes de aves como veiculo de contaminacao, e armazenados a 8°C e 70% de umidade relativa ou a 30°C e 90% de umidade relativa. A 8°C, o microrganismo permaneceu viavel na superficie dos ovos, ao longo do tempo, enquanto a 30°C foi possivel identificar a sua inibicao e ate sua eliminacao da superficie. A contaminacao do conteudo de ovos com defeito de casca foi mais frequente quando os ovos foram submetidos a temperaturas inadequadas de armazenagem (30°C).

Evaluation of physico-chemical characteristics of fresh, refrigerated and frozen Lacaune ewes' milk

The production of ewe milk is seasonal and milk yield per animal is low, even in specialized animals. This study aimed to verify the possibility of preserving bulk tank milk for seven days under cooling (5°C) and freezing (-5°C), verify the influence of cooling treatments and of the months of the year on the physical and chemical characteristics of the product. The chemical composition of milk, including the fat, protein, lactose and total solids contents, was not altered by cooling and freezing. Protein and lactose contents varied according to the months of the year. The average percentage and standard deviation of fat, protein, lactose and total solids was 8.10±1.30, 5.22±0.37, 4.43±0.23 and 19.34±1.54, respectively. The density, pH, titratable acidity, as well as alcohol and heat stability tests were significantly influenced by the treatments used (P < 0.05), but no differences were found between fresh and frozen milk. Prolonged refrigeration caused an increase in acidity and decrease in pH, with a consequent reduction in the stability of milk. These results demonstrated that freezing does not affect the chemical composition and physical characteristics of milk in nature and it could be a solution for the producer and the sheep milk industry.

Isolated or associated experimental contamination of albumen and egg yolk for Salmonella Enteritidis and Escherichia coli: influence of temperature and storage time

Avaliou-se o comportamento de Salmonella enteritidis (SE) e Escherichia coli em albumen e gema de ovos de galinha, submetidos a duas diferentes temperaturas, 8 e 30oC, quando inoculadas isoladamente ou na forma de culturas mistas. Nao houve diferenca no comportamento dos agentes testados mesmo quando inoculadas em conjunto. Mesmo sob temperatura alta, E. coli nao se multiplicou no albumen, demonstrando o poder inibidor de seus constituintes para esse microrganismo, enquanto a SE aumentou sua populacao em ate tres ciclos logaritmicos. Em gema de ovo, SE demonstrou caracteristicas psicrotroficas.

Rendimento de coalhada obtida a partir de leite fresco, resfriado e congelado de ovelhas da raça Lacaune e caracterização física do soro obtido

Milk composition that can be affected by cooling or freezing is crucial for the performance of chesese making, and it is an important parameter in economic terms. The objective of this study was to evaluate, during 7 days, the effect of milk cooling and freezing on the yield of the curd produced with the sheep milk and on the physical characteristics of the obtained whey. Between January and December 2011 samples of the sheep milk were collected every month, directly from the bulk tanks. A part of it was subject to analysis in the same day, and the rest was stored for up to 7 days. One of the samples was kept under refrigeration (5°C - cooled milk) and another was kept in a domestic freezer (-4°C - frozen milk). The yield and density of the curd, pH and titratable acidity of the obtained whey was determined. The treatment applied showed a significant difference (P<0.05) in the yield of the curd, whereas the yield obtained with the cooled milk (3.64±0.34L kg-1) and the frozen milk (3.18±0.23L kg-1) showed no differences with the fresh milk (3.38±0.22 L kg-1), but these treatments were not the same. The average density of the obtained whey (1.025g mL-1) did not present differences between the applied treatments. The whey pH and titratable acidity were similar in both fresh and frozen milk treatments, but there was a difference (P<0.05) with the cooled milk, which had a higher acidity. Even though the whey of the curb obtained from the cooled milk is more acid, the cooling and freezing of the sheep milk, for a period of 7 days, do not affect the yield in cheese making, and the obtained whey does not present density differences between the applied treatments.

Evaluation of microscopic protocols for somatic cell counts in milk of dairy sheep

Arq. Inst. Biol., v.85, 1-4, e0962016, 2018 ABSTRACT: The somatic cell count (SCC) is a diagnostic tool that indicates the mammary gland health and can be determined by the counting of cells in the microscope. There are discussions regarding appropriate staining method to the ewes’ milk. The present study aimed to identify a methodology of microscopic SCC proper to the milk of the ovine species. Therefore, glass slides for smear were manufactured with 10 μL of ewe’s milk in 1 cm2, and the fixers xylol and Carnoy’s solution were tested, as well as and May‐Grünwald, Broadhurst‐Paley, Wrigth and Panoptic stainings. Carnoy’s solution was elected, because it allowed a better fixation of the dairy film to the microscope slides, and Broadhurst‐Paley staining, due to its good coloration and visualization of cells, as well as the differentiation of cytoplasmic corpuscles in ewe’s milk. Broadhurst‐Paley coloration is a tool applicable to the somatic cell count in ovine specie’s milk.

IMPLICATIONS OF THE QUALITY OF THE PRODUCTION PROCESS ARTISAN CHEESE SERRANO

The Serrano Handmade Cheese (SHC) is a product manufactured on high altitude fields in southernmost Brazil. This region is formed by northeastern Rio Grande do Sul and Santa Catarina Southern Plateau. Originally, this was a overplus good exchanged for another goods by drovers of this region. Currently, the SHC may be responsible for up to 60% of properties income. The SHC is produced with raw milk from cattle ranching within the property. Thus, was performed a descriptive study of literature review aiming to describe the production process of Serrano Handmade Cheese. A look on product quality and food safety theoretical contribuiton was sought also. Considering the technical regulation development to SHC some properties has build appropriate production environments. Those actions are aiming quality and safety of the cheese made. The implementation of Good Agricultural Practice has shown significant quality improvement of the milk used to produce this cheese. The implementation of Good Manufacturing Practice is under study in these producing properties.

Parâmetros de qualidade do leite de cabra armazenado sob frio

The small-scale goat milk production requires its storage, and such operation is allowed by Brazilian laws. This study aimed at evaluating the cooling and freezing effects on physical-chemical and microbiological characteristics of goat milk. However, no variability was verified in average acidity, alcohol stability, density, fat protein, total solids and lactose values after cold storage. Heat instability was not observed in any of the analyzed samples. There was a decreasing tendency in the somatic cell count (SCC) of frozen milk in comparison to fresh and refrigerated milk. The quantification (NMP) of total and thermo-tolerant coliforms varies from 1,100 UFC/mL, regardless of the storage method. However, a slightly higher count (p < 0.0001) was observed for total and thermo-tolerant coliforms in the samples kept under refrigeration. In the lacto-fermentation test, digested, flocculated and grooved clots were observed without establishing a correlation between them and the bacterial count. SCC and microbial count are the criteria adopted when paying for the quality of goat milk, and the storage temperature may affect these criteria.