Cleube Andrade Boari

Avaliação higiênico-sanitária de linguiças tipo frescal comercializadas nos municípios de Três Corações e Lavras MG

Com o presente trabalho, objetivou-se avaliar a qualidade higienico-sanitaria de linguicas tipo frescal, em funcao do potencial risco que estes produtos representam para a saude publica. Para a conducao de tal pesquisa, amostras foram aleatoriamente coletadas no municipio de Tres Coracoes (n=20) e Lavras (n=20), ambos situados no Estado de Minas Gerais. As analises microbiologicas, conduzidas de acordo com o ICMSF (1982), constaram da enumeracao de coliformes totais e termotolerantes (colimetria), quantificacao e identificacao bioquimica de Staphylococcus coagulase positiva e Salmonella spp. Nao foi detectada a presenca de Salmonella spp. em nenhuma das amostras. Os valores para contaminacao por coliformes termotolerantes encontraram-se dentro do intervalo de 101 a 104 NMP/g. Em 14% das 40 amostras analisadas foi detectado Staphylococcus coagulase positiva acima do limite estabelecido pela legislacao vigente. Pelos valores encontrados, as linguicas analisadas nao sao produzidas dentro de padroes de higiene satisfatorios, sendo um potencial causador de toxinoses e infeccoes alimentares aos consumidores.

Formação de biofilme em aço inoxidável por Aeromonas hydrophila e Staphylococcus aureus usando leite e diferentes condições de cultivo

The aim of this research was to verify the capability of biofilm formation on stainless steel by Aeromonas hydrophila and Staphylococcus aureus using milk and different conditions of cultivation. The variables consisted in mono and multi-species cultivation of these microorganisms and in the temperatures of 4, 7 and 18 °C. Containers containing 1000 mL of milk, population density of 10 5 CFU.mL –1 of each microorganism, and ten suspended chips of stainless steel AISI 304 (10 × 20 mm) were used to seal up and storage, under 60 rpm of agitation for 10 days. The analyses were conducted every 48 hours. Sessile cells of A. hydrophila and S. aureus and were enumerated by plating in m-Aeromonas selective agar and Baird-Parker agar. Complementary studies included the generation time calculation, enumeration of planktonic cells, and visualization of chips by scanning electron microscopy. S. aureus, in mono-cultivation, formed biofilm at 18 °C and at 7 °C. At 4 °C was observed attachment. The presence of A. hydrophila reduced the performance of S. aureus. In this condition, S. aureus formed biofilm at 18 °C. A. hydrophila formed biofilm under all conditions.

Bacterial ecology of tilapia fresh fillets and some factors that can influence their microbial quality

The purpose of research was to investigate the bacterial ecology of tilapia (Oreochromis niloticus) fresh fillets and some factors that can influence its microbial quality. Samples of fish cultivation water (n = 20), tilapia tegument and gut (n = 20) and fresh fillets (n = 20) were collected in an experimental tilapia aquaculture located in the city of Lavras, Minas Gerais, Brazil. Staphylococcus spp., Aeromonas spp., Enterococcus spp. and Enterobacteriaceae were quantified using selective plating. For the enumeration of Pseudomonas spp., the most probable number technique (MPN) was utilized. Bacterial colonies (n = 198) were identified by Gram strain and biochemical tests. Aeromonas spp., Pseudomonas spp., Enterococcus spp. and Enterobacteriaceae were found in the cultivation water (water from a fishpond cultivation), tegument, gut, and fresh fillets. Staphylococcus spp. was not isolated in the cultivation water. Salmonella spp. was not detected. The count variable of 10 to 103 CFU or MPN.(g or mL)-1. Associated to freshwater tilapia fillet processing, there is a large variety of microorganisms related to foodborne illnesses and fish products deterioration.

Isolamento de coliformes, estafilococos e enterococos de leite cru provenientes de tanques de refrigeração por expansão comunitários: identificação, ação lipolítica e proteolítica

Isolation and identification of microorganisms in raw milk is interesting from the viewpoint of public health, since, depending on the species isolated, directed actions may be taken to improve milk quality. Milk deterioration is mainly the result of the growth of psychrotrophic microorganisms that produce heat-resistant lipases and proteases which are not denatured during pasteurization, conferring rancid and sour flavors, respectively. Thus, this work aimed at isolating and identifying the main genera of bacteria belonging to the Enterobacteriaceae family, oxidase-positive Gram-negative, Staphylococcus and Enterococcus genera, as well as determining lipase and protease activity in 16 rural farms in Boa Esperanca-MG, Brazil. The Gram-negative bacteria were isolated in Eosin Methylene Blue (EMB) and Hektoen Enteric agar media. Staphylococci were isolated in Baird-Parker agar and Enterococcus in KF agar. Colonies of interest were collected and submitted to Gram stain and to catalase and oxidase tests. Following these procedures, the isolates selected were identified using Bactray I, II and III; Api 20 Strep and tests suggested by Bergeys Manual of Determinative Bacteriology. Sorological identification of Enterococcus was carried out using Prolex. Milk from the 16 rural properties contained strains of fecal microorganisms, such as Escherichia coli and Enterococcus from the Lancefield D group. Oxidase-positive Gram-negative bacteria were identified in five farms. Staphylococcus was found in 10 farms. Milk collected from the farms investigated contained microorganisms that compromise its quality. All the microorganism groups tested showed lipase and protease activities.

Influência da embalagem na vida útil de presuntos fatiados

The aim of this work was to compare the shelf-life of sliced ham without fat layer storage in a range of temperature between 1o and 4oC using the following treatments: vacuum packing (VP) and packing with modified atmosphere (MA) (50% of N2 and 50% of O2) using flexible sheets of PEAD/LDPE (MA1) and PVDC/EVA/LDPE (MA2) on microbiological and physical chemical parameters for 35 days. Analysis of plate count of microorganisms, pH and humidity were conduced to evaluate the shelf-life of ham. In the first day of analyze the countings of Staphylococcus aureus had been inferior to 102 CFU/g and for the other microorganisms inferior to 101 CFU/g. The packed with modified atmosphere increased five days in the shelf-life of the product when compared to vacuum packing. The initial pH (6.4) increased to 6.55, 6.58 and 6.63 on VP MA1 and MA2, respectively. The treatment MA2 increased the shelf-life when compared to modified atmosphere (1).