Ronaldo Tamanini

Listeria monocytogenes: Occurrence in beef and identification of the main contamination points in processing plants.

This study aimed to establish the occurrence of Listeria spp., especially L. monocytogenes and its main serotypes, in beef and processing plants. A total of 443 samples were obtained from equipment, installations and products from 11 meat processing establishments from Paraná state, Brazil. All samples were analyzed using USDA methodology for Listeria spp. detection, followed by species identification. The occurrence of Listeria spp. in the samples was 38.1% of which 51.4% were from equipment, 35.4% from installations and 30.2% from products. The identified species were: L. monocytogenes (12.6%), L. innocua (78.4%), L. seeligeri (1.2%), L. welshimeri (7.2%) and L. grayi (0.6%). The identified serotypes of L. monocytogenes were 1/2a and 4b. The results demonstrate the significance of equipment and installations as sources of contamination by Listeria spp. and L. monocytogenes in the processing of beef and meat products.

The main spoilage-related psychrotrophic bacteria in refrigerated raw milk

Refrigerated raw milk may contain psychrotrophic microorganisms that produce thermoresistant exoproteases and lipases, which may compromise the quality of processed fluid milk and dairy products during storage. The aim of this work was to quantify and identify the deteriorating psychrotrophic microbiota in Brazilian refrigerated raw milk using genetic diversity analysis. The mean psychrotrophic count was 1.1 × 104 cfu/mL. Of the total isolates, 47.8 and 29.8% showed deteriorating activity at 35°C within 48 h and 7°C within 10 d, respectively. Among the proteolytic species, more isolated by this study were Lactococcus lactis (27.3%), Enterobacter kobei (14.8%), Serratia ureilytica (8%), Aerococcus urinaeequi (6.8%), and Bacillus licheniformis (6.8%). Observed among lipolytics were E. kobei (17.7%), L. lactis (15.6%), A. urinaeequi (12.5%), and Acinetobacter lwoffii (9.4%). The isolates S. ureilytica, E. kobei, Pseudomonas spp., and Yersinia enterocolitica potentially produced alkaline metalloprotease (aprX). Despite the low counts, a considerable portion of the psychrotrophic microbiota presented spoilage potential, which reaffirms the need for rigor in the control of contamination and the importance of rapid processing as factors that maintain the quality of milk and dairy products.

Microbiota mesófila aeróbia contaminante do leite UHT

In 2011 the national production of ultra-high temperature milk (UHT) was 5.81 billion liters, corresponding to 78% of fluid milk consumed in Brazil. The present work aimed to study UHT milk contamination by mesophilic aerobes (MA), verifying the accordance with microbiological standards, classifying the groups found according to its morpho-tinctorial characteristics and discussing the methodology determined by Normative Instruction (NI) 62 from the Brazilian Ministry of Agriculture, Animal Husbandry and Supply. From 60 studied samples, 23 (38.3%) presented results above the 100 CFU/mL standard established by NI 370 for (MA). When B. sporothermodurans was considered, maximum counts raised 71.2% in whole milk samples, and 31.0% in skimmed milk samples. Regarding the higher dilutions inoculated that have shown growth, it was possible to isolate 462 colonies of (MA) that, in Gram coloration corresponded to 64.3% Gram positive bacteria and 9.5% Gram negative. Molds and yeasts added up to 26.2%. Among Gram positive, there was a prevalence of cocci, B. sporothermodurans , and other Gram positive bacilli. Among Gram negative, the coccobacilli and bacilli prevailed. Considering that the samples represent UHT milk from important industries of southern Brazil, the results demonstrate that 11 out of the 15 studied brands showed high counts of (MA) when compared to the established standards. Furthermore, among the groups of microorganisms found in the samples, especially heat sensitive Gram negative bacteria, indicates possible failures in milk processing and/or post-processing contamination.

ESTABILIDADE TÉRMICA DA CASEÍNA E ESTABILIDADE AO ÁLCOOL 68, 72, 75 E 78%, EM LEITE BOVINO

Milk heat stability, evaluated through alcohol or alizarol test, is affected by several factors, the main one is milk acidificat ion. However, enzymatic hydrolysis, high somatic cells counts (SCC), excess of calcium ions and ethanol addit ion also af fect its stability to alcohol , reducing its correl ation with heat stability. The objective of this work was to determine the occurrence of instable non acid milk (LINA) in Sapopema-PR, evaluate heat stability of LINA and its relation with SCC and total bacteria count (TBC) and also evaluate the interference of alcohol concentration, used to perform alcohol test, on milk stability. A total of 85 samples were submit to alcohol test at 68, 72, 75 e 78%, determination of Dornic acidity, boiling test , SCC and TBC. High occurrence of LINA was observed. The highest frequency of LINA 65,88% occurred at alcohol concentration of 78% v/v and the lowest 15,29% at 68% v/v. With one exception, LINA samples were stable to boiling test, showing that its rejection by industry that produces pasteurized milk and dairy products would be unnecessary. The means obtained to SCC and TBC were elevated in both LINA samples and instable samples with acquired acidity.

Avaliação da qualidade microbiológica e físicoquímica do leite cru refrigerado produzido na região de Ivaiporã, Paraná

The aim of this work was to evaluate the microbiological and physico-chemical parameters of refrigerated raw milk produced in 99 dairy farms from Ivaipora-PR region, from August to October 2010. Samples out of standards for that period of time were observed to all analysis determined by legislation: alizarol 72% v/v (63,38%), titratable acidity (54,05%), crioscopy (8,10%), density (5,4%), fat (17,17%), total protein (14,14%), non-fat solids (26,26%), SCC (17,17%) and TBC (54,08%). Frauds by water addition and skim of milk were observed. Results suggest de cient milking hygiene and lack of sanity control of mammary gland, showing that the legislation goals for milk quality improvement initiated at 2002 are not being achieved by the producers.The aim of this work was to evaluate the microbiological and physico-chemical parameters of refrigerated raw milk produced in 99 dairy farms from Ivaipora-PR region, from August to October 2010. Samples out of standards for that period of time were observed to all analysis determined by legislation: alizarol 72% v/v (63,38%), titratable acidity (54,05%), crioscopy (8,10%), density (5,4%), fat (17,17%), total protein (14,14%), non-fat solids (26,26%), SCC (17,17%) and TBC (54,08%). Frauds by water addition and skim of milk were observed. Results suggest deficient milking hygiene and lack of sanity control of mammary gland, showing that the legislation goals for milk quality improvement initiated at 2002 are not being achieved by the producers.

AVALIAÇÃO DA QUALIDADE FÍSICO-QUÍMICA E MICROBIOLÓGICA DE CREMES DE LEITE UHT

UHT products consumption has increased in Brazil, due to its practical storage and long shelf life. The aim of the present work was to verify physico-chemical and microbiological quality of UHT milk cream, commercialized in Londrina-PR. A total of 14 brands were evaluated, three samples for each brand were collected, toting up 42 samples. Regarding fat content, 26,19% of samples did not present the percentage described on the carton of the product, and the other 73,81% presented the expected percentage of label or superior values. As for acidity analysis, none of the results found had values superior than standard established by law. For mesophilic aerobes count, only one sample (2,38%) presented counts higher than standard of 100CFU/g of milk cream established by MAPA (Brazilian Ministry of Agriculture Livestock and Supply, that inspects products at industry). On the other hand, 73,80% were out of standard according with ANVISA (Brazilian National Agency for Sanitary Surveillance, which establishes standards for food safety assurance at the market). The remaining samples (23,80%) did not present any growth. From 110 isolated colonies of BHI agar and nutrient agar, all were Gram positives from which 48,20% were bacillus, 41,8% were cocci, 7,3% with suggested yeast morphology, 1,8% were coccobacillus and 0,9%were diplococci. The most frequent problem evidenced by the present work was fat content lower than described on carton. Microbiological standards established for UHT milk cream by different government institutions are ambiguous and difficult product assessment. Using both standards, the majority of samples presented satisfactory quality according with industry legislation and, at the same time, were out of standards for the market.

IMPACTO DA IMPLANTAÇÃO DE BOAS PRÁTICAS DE HIGIENE NA ORDENHA SOBRE A QUALIDADE MICROBIOLÓGICA E FÍSICO-QUÍMICA DO LEITE CRU REFRIGERADO

Normative instruction no 62 brought new standards to be followed by producers, proceeding to continue the improvement of milk quality in progress since Normative instruction no 51. However quality improvement of milk did not occur as fast as expected. The aim of this work was to evaluate the impact of good practices on milk quality in 49 dairy farms located in Ivaipora/PR, through collective lectures and training courses. A reduction of 88,05% in Total Bacterial Count (TBC) in 28 (57,15%) dairy farms that implemented the good practices was observed. From those farms, 23 (47,93%) presented TBC bellow maximum of 750.000 CFU/mL as required by legislation at the period of analysis, with average counts of 166.826,1 CFU/mL. As for Somatic Cell Counts (SCC), 83,57% of all farms began to produce milk according with the standard set to this item at the time of analysis. Significant variations were not observed in physico-chemical parameters of milk after practices implementation. Implementation of the proposed practices was sufficient to produce milk according with standards established by legislation.