Major Causes of Variation of External Appearance, Chemical Composition, Texture, and Color Traits of 37 Categories of Cheeses.

Cheeses are produced by many different procedures, giving rise to many types differing in ripening time, size, shape, chemical composition, color, texture, and sensory properties. As the first step in a large project, our aim was to characterize and quantify the major sources of variation in cheese characteristics by sampling 1050 different cheeses manufactured by over 100 producers and grouped into 37 categories (16 with protected designation of origin, 4 traditional cheese categories, 3 pasta filata cheese categories, 5 flavored cheese categories, 2 goat milk categories, and 7 other categories ranging from very fresh to very hard cheeses). We obtained 17 traits from each cheese (shape, height, diameter, weight, moisture, fat, protein, water soluble nitrogen, ash, pH, 5 color traits, firmness, and adhesiveness).

Assessment of the microbiological origin of blowing defects in Grana Padano Protected Designation of Origin cheese.

Recognized worldwide for its history, flavor, and high nutritional quality, Grana Padano (GP) is one of the most traditional Italian raw-milk, hard-cooked, long-ripened cheese. Throughout GP manufacturing, some well-known and undesired bacterial species, such as clostridia, can proliferate and lead to spoilage defects that mischaracterize the final product; however, little is known about the development of late-blowing defects in hard cheese samples without clostridia. Therefore, in this study we aimed to use metataxonomic analysis to identify bacterial taxa associated with the development of late-blowing defect in GP samples.

Thermal resistance and high-performance microwave decontamination assessment of Bacillus endospores isolated from food-grade herbal extracts.

Generally, endospore contamination can occur from different sources during product manufacturing in many industries and therefore lower its quality by affecting physicochemical properties and shelf-life. Bacterial endospores can germinate inside the product and produce several enzymes, which can cause several undesirable changes. This study assessed the spores thermal resistance and applied a microwave decontamination technique toward herbal extracts (Tilia tomentosa and Centella asiatica) containing ethanol or glycerol.

The Geographic Distribution of Isolates within three Italian Neighboring Winemaking Regions Reveals Strong Differences in Yeast Abundance, Genetic Diversity and Industrial Strain Dissemination.

In recent years the interest for natural fermentations has been re-evaluated in terms of increasing the wine and managing more sustainable winemaking practices. Therefore, the level of yeast genetic variability and the abundance of native populations in vineyard are becoming more and more crucial at both ecological and technological level. Among the factors that can influence the strain diversity, the commercial starter release that accidentally occur in the environment around the winery, has to be considered.

Analysis of Process Factors of Dry Fermented Salami to Control .

Challenge tests are a clear opportunity for manufacturers interested in the evaluation of their management system with the aim to reduce the spread of foodborne pathogens. This is a main concern especially in ready-to-eat food in relation to the risk associated with . For small and medium-scale food industry the manufacturing practices and products formulation are characterised by a wider variability and poor repeatability.

Genome comparison and physiological characterization of eight Streptococcus thermophilus strains isolated from Italian dairy products.

Eight Streptococcus thermophilus strains of dairy origin isolated in Italy were chosen to investigate autochthonous bacterial diversity in this important technological species. In the present study a comparative analysis of all the 17 S. thermophilus genomes publicly available was performed to identify the core and the variable genes, which vary among strains from 196 to 265.

Isolation and characterisation of lactic acid bacteria from donkey milk.

During the last years the interest in donkey milk has increased significantly mainly because of its compelling functional elements. Even if the composition and nutritional properties of donkey milk are known, its microbiota is less studied. This Research Communication aimed to provide a comprehensive characterisation of the lactic acid bacteria in raw donkey milk.

Outlining a selection procedure for Saccharomyces cerevisiae isolated from grape marc to improve fermentation process and distillate quality.

Nowadays grape marc represents one of the main by-product of winemaking. Many South Europe countries valorize this ligno-cellulosic waste through fermentation and distillation for industrial alcoholic beverage production. The storage of marcs is a crucial phase in the distillation process, due to the physicochemical transformations ascribed to microbial activity.

Exploring the use of Saccharomyces cerevisiae commercial strain and Saccharomycodes ludwigii natural isolate for grape marc fermentation to improve sensory properties of spirits.

In Mediterranean countries the most diffuse practice to obtain the valorization of grape marc, the main by-product from winemaking, is the production of spirits. During this process, marc storage for sugar fermentation represents a crucial step, since side-fermentations leading to off-flavours production can very easily occur. In this study we evaluated the effect of the addition of two yeast strains, inoculated separately at the beginning of the storage period, into marcs from two Italian grape varieties with the aim to control the development of autochthonous microbiota and to improve spirit quality.

Biodiversity and characterization of indigenous coagulase-negative staphylococci isolated from raw milk and cheese of North Italy.

The aim of the current study was to detect coagulase-negative staphylococci (CNS) in raw milk and cheeses produced in North Italy, and to analyze isolates for their biodiversity, safety aspects and technological properties. Molecular identification methods revealed a high biodiversity among isolates and assigned them to 17 species. The most recovered species were Staphylococcus equorum (12%), Staphylococcus lentus (12%), Staphylococcus simulans (12%), Staphylococcus sciuri (10%), and Staphylococcus xylosus (9%).

A longitudinal study on thermophilic Campylobacter spp. in commercial turkey flocks in northern Italy: occurrence and genetic diversity.

Poultry are recognized as a main reservoir of thermophilic campylobacters, but few studies have been carried out on commercial meat turkeys. This study was aimed at assessing the occurrence of thermophilic Campylobacter spp., their genetic diversity, and the trend of the infection during the whole production cycle of three turkey flocks from different farms in Northern Italy.

Identification of microbiota present on the surface of Taleggio cheese using PCR-DGGE and RAPD-PCR.

Unlabelled: Microbial DNA from 9 batches of Taleggio PDO cheese sampled at various times during ripening, brines, swabs of wooden shelves used for cheese dry-salting, and 13 commercial cheeses were analyzed by denaturing gradient gel electrophoresis (PCR-DGGE) and/or random amplification of polymorphic DNA (RAPD-PCR). Sequencing allowed the detection of 12 genera, 27 species, and 2 unclassified bacteria. Molecular analysis allowed for the detection of microorganisms not previously associated with Taleggio such as Lactobacillus paracasei, Carnobacterium maltaromaticum, Bacillus licheniformis, Corynebacterium variabile, Psychrobacter cibarius, and Staphylococcus carnosus.

Phenotypic and Genotypic Characterization of Staphylococcus aureus Strains from Italian Dairy Products.

Staphylococcus aureus is a known major cause of foodborne illnesses, and milk and dairy products are often contaminated by enterotoxigenic strains of this bacterium. In the present study, 122 S. aureus isolates collected from different dairy products were characterised by phenotypic properties, by the distribution of genes encoding staphylococcal enterotoxins (sea, sec, sed, seg, seh, sei, sej, and sel) and by randomly amplified polymorphic DNA PCR (RAPD-PCR).

Yeast population dynamics during pilot-scale storage of grape marcs for the production of Grappa, a traditional Italian alcoholic beverage.

The composition and population dynamics of the yeast microflora of grape marcs were investigated during a pilot scale fermentation study using two white grape varieties, namely Moscato and Prosecco, from two distinct areas of the Veneto Region. Yeast counts were made at the beginning, after 4 and after 15 days of marc storage under anaerobic conditions. Seventy isolates from each sampling time were identified to species by RAPD-PCR analysis and subsequent ITS region sequencing.

Occurrence of Streptococcus macedonicus in Italian cheeses.

A new approach for the detection and enumeration of Streptococcus macedonicus in cheese was developed. The method which is based on a first screening of cheeses by a PCR assay specific for S. macedonicus followed by plating positive samples on a differential medium (SM medium) was applied to 51 samples derived from PDO and traditional Italian cheeses.

A polyphasic approach to highlight genotypic and phenotypic diversities of Lactobacillus helveticus strains isolated from dairy starter cultures and cheeses.

In the present work, 67 strains of Lactobacillus helveticus isolated from whey starter cultures and cheeses were identified and grouped by genotypic and phenotypic methods. Strains were identified by sugar fermentation pattern, by cell-wall protein profile, and by probe hybridisation. Phenotypic diversity was evaluated by a chemometric model taking into account biochemical characteristics (i.

Biochemical and genetic characterization of the two-peptide bacteriocin enterocin 1071 produced by Enterococcus faecalis FAIR-E 309.

The structural genes for the two-peptide bacteriocin enterocin 1071 (Ent1071) in Enterococcus faecalis FAIR-E 309 were cloned. DNA sequence analysis showed that the enterocin 1071A (Ent1071A) peptide of strain FAIR-E 309 differed by two amino acids from the Ent1071A reported for E. faecalis BFE 1071 (E.

Intraspecies genomic groups in Enterococcus faecium and their correlation with origin and pathogenicity.

Seventy-eight Enterococcus faecium strains from various sources were characterized by random amplified polymorphic DNA (RAPD)-PCR, amplified fragment length polymorphism (AFLP), and pulsed-field gel electrophoresis (PFGE) analysis of SmaI restriction patterns. Two main genomic groups (I and II) were obtained in both RAPD-PCR and AFLP analyses. DNA-DNA hybridization values between representative strains of both groups demonstrated a mean DNA-DNA reassociation level of 71%.