and from refrigerated raw milk: genetic diversity and lipoproteolytic activity.

In this research communication the genetic diversity of Pseudomonas fluorescens (n = 67) and Pseudomonas putida (n = 44) isolated from refrigerated raw milk from bulk tank trucks were verified. The relationship between the genetic profile of the isolates and their lipoproteolytic potential was evaluated using skim milk agar and tributyrin agar (21°C/72 h). The lipoproteolytic potential (low or high), evaluated by the diameter of the halos (cm), was correlated with the number of milk producing properties that contributed to each sample (one sample = one bulk tank truck; 8-80 producers/sample) and the distance between the dairy properties and the processing plant (21-370 km).

Occurrence and seasonality of aflatoxin M1 in milk in two different climate zones.

Background: Aflatoxin M1 (AFM1) is a mycotoxin found in milk as a result of the ingestion of aflatoxin B1 (AFB1) by dairy cattle. Because of its carcinogenic properties, the control of its occurrence in dairy products is of great importance. We evaluated the occurrence and seasonality of AFM1 in milk from farms with subtropical and temperate climates, where significant milk production occurs.

Changes occurring in stabilized ultra-high-temperature-treated whole milk during storage.

This Research Communication describes the relationship between casein, free fatty acids (FFAs) and the storage period of ultra-high temperature-treated (UHT) whole milk observed for a period of 120 d of labelled shelf-life. Moreover, we aim to estimate the daily rate of casein degradation in UHT whole milk, and the total length of time estimated for its full degradation. With this aim, ten sets of samples were evaluated from batches of UHT milk manufactured by a dairy processing plant in Parana State, Brazil on 10 different days.

Milk adulteration with acidified rennet whey: a limitation for caseinomacropeptide detection by high-performance liquid chromatography.

Background: High-performance liquid chromatography (HPLC) is widely employed to determine the caseinomacropeptide (CMP) index and to detect milk tampering with rennet whey. Prior to HPLC analysis, CMP is subject to a trichloracetic acid isolation, causing further soluble proteins in the sample to precipitate. On this basis, we aimed to determine whether rennet whey acidification could adversely affect the HPLC sensitivity with respect to detecting this peptide.

Sheep milk: physical-chemical characteristics and microbiological quality.

Sheep milk is the third most consumed milk in Brazil. It is much appreciated for its nutritional status and is important for children that have problems with cow milk. Little information is known about the chemical, physical and microbiological composition of sheep milk from South Brazil.

Viability of probiotic Lactobacillus casei in yoghurt: defining the best processing step to its addition.

Probiotics are live microorganisms capable of producing beneficial effects on its host when consumed in adequate amounts. To exert these effects, foods must contain probiotic microorganisms in populations above 10(6) CFU/g or mL throughout its shelf life. One of the strategies to ensure high population of probiotics in fermented milk is to add them during or after the fermentation process separately from the starter cultures.

Antimicrobial action of lactoferrin on Staphylococcus aureus inoculated in Minas frescal cheese.

The effect of the addition of lactoferrin on Staphylococcus aureus to Minas frescal cheese was evaluated. Three cheeses were made: control (S. aureus), Lf-2% (2% lactoferrin + S.

[Physico-chemical and microbiological evaluation of UHT milk commercialized in three Mercosul countries (Brazil, Argentina and Paraguay)].

With the aim to evaluate the physico-chemical and microbiological quality of UHT milk commercialized in three countries of Mercosul, samples of four different brands were acquired in each city (Foz do Iguaçu-Brazil, Puerto Iguazú-Argentina and Ciudad del Este-Paraguay) and submitted to the following analysis: fat content, titratable acidity, milk ethanol stability (with the following ethanol concentrations: 68, 72, 76 and 80%), total dry extract and no fat dry extract, pH, density and freezing point. Counts of mesophilic and psychrotrophic microorganisms were already done. In the physico-chemical evaluation of UHT milk, a significant number of samples were in disagree with the established patterns for fat content, no fat dry extract, density and freezing point.