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Processi tradizionali e polifenoli naturali per formaggi innovativi e nutraceutici
Full text linkl’aggiunta di composti antiossidanti naturali nei prodotti caseari
ne aumenta il valore nutrizionale e il periodo di conservabilita
Microbiological characterization of the biofilms of wooden shelves used for ripening of traditional raw milk cheeses produced in Sicily (South Italy).
No full textThe production of artisanal Sicilian cheeses is generally carried out with wooden equipment. For centuries, wood has been the main material used in cheese making due to its availability, low cost and resistance over time. Among dairy wooden equipment, the wooden vat used for milk curdling plays a role of paramount importance to inoculate the bulk milk with desired lactic acid bacteria (LAB) responsible for the acidification of the curd. In the last few years, the biofilms associated to these containers have been object of study of different research groups, mainly Italian and French, but so far, very little is known about the microbiological characteristics of the wooden shelves used for cheese ripening and their influence on the safety of the final products. With this in mind, the aim of the present study was to investigate and enumerate several microbial populations associated to the wooden shelves used for the ripening of traditional Sicilian cheeses. To this purpose, the biofilms of nine wooden shelves used for the ripening of Caciocavallo Palermitano and PDO Pecorino Siciliano made with raw cows’ and raw ewes’ milk, respectively, were investigated. The shelf biofilms (400 cm2) were sampled by the brushing recovery method using sterile plastic squares (Biogenetics s.r.l., Padua, Italy). The cell suspensions of wooden shelves were subjected to the decimal serial dilutions in Ringer’s solution (Sigma-Aldrich, Milan, Italy). The microbiological investigation carried out by plate count involved pro-technological and spoilage/pathogenic bacterial groups and unicellular/filamentous fungi. Listeria monocytogenes, Salmonella spp. and coagulase-positive staphylococci were never detected, total coliforms were at low numbers with E. coli found only onto two shelves. The spores of clostridia were not detected in any shelf. LAB dominated the surfaces of seven shelves, but they were below the detection limit onto two shelves. In general, the dominance was showed by mesophilic LAB cocci found in the range 105 - 108 CFU/cm2. Enterococci were found only onto three wooden shelves, but almost at 2 Log cycles lower than the levels of mesophilic LAB. Pseudomonas spp. were found only onto three shelves, also positive for the presence of enterobacteria. Yeasts were found in all samples and their levels ranged between 1.60 and 6.81 Log CFU/cm2. Moulds were below the detection limit only in one sample and their levels ranged between 1.78 and 5.45 Log CFU/cm2 on the other shelves. This study represents a first report on the microbiological investigation of the biofilms associated to the wooden shelves used for cheese ripening in Sicily. The results of the present work confirmed that from a hygienic point of view, the wooden shelves do not represents a risk for the safety of consumers. However, further studies are necessary to better investigate the microbial composition of these dairy equipment at species level in order to evaluate their influence on the centripetal ripening
Dominant lactic acid bacteria in naturally fermented milks from Messinese goat's breed
Full text linkBackground: Lactic Acid Bacteria (LAB) are an important group of microorganisms responsible for the fermentation dairy products. This study was done to identify the dominant lactic acid bacteria in naturally fermented milks from Messinese goat's breed. Methods: Eighteen individual raw milk samples collected from Messinese goat's breed were acidified at pH 5.20 and left to spontaneously ferment at 37 °C for 4 days. All samples were analyzed for rod- and coccus-shaped LAB. Also, all presumptive LAB were isolated and differentiated according to their phenotypic properties and genetic polymorphisms and then identified by sequencing the 16S rRNA gene. Data were statistically analyzed using SAS 9.2 software. Results: Levels of coccus- and rod-shaped LAB were in the range of 1.78-7.10 log and 1.00-7.09 log colony forming unit/ml, respectively. The microbiological counts on the two different growth media were significantly (p < 0.05) different among the samples. Among 12 identified strains, the most numerous one was Enterococcus hirae (n=4), followed by E. faecium (n=3), while the other species (E. durans, E. faecalis, E. lactis, Lactococcus lactis, and Leuconostoc lactis) included one strain each. Conclusion: The major group identified in this study was mainly represented by members of Enterococcus genus. Although Enterococcus spp. are related to the typicality of some traditional fermented dairy products, this study highlights the need for risk assessment of pathogenic enterococci species for the consumers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Microbiological Analysis and Metagenomic Profiling of the Bacterial Community of an Anthropogenic Soil Modified from Typic Haploxererts
Full text linkThis work aimed to characterize the microbial communities of an anthropogenic soil originating from application of pedotechniques to Vertisols in a Mediterranean environment. Bare soil profiles were sampled at three depths (0–10 cm, 10–30 cm, and 30–50 cm) and compared with the original soil not transformed at the same depths. The anthropogenic soils were characterized by a higher CaCO3 concentration (360–640 g/kg) than control soil (190–200 g/kg), while an opposite trend was registered for clay, where control soil showed a higher concentration (465 g/kg on average) than anthropogenic soil (355 g/kg on average). Organic carbon content was much higher in the untransformed soil. All samples were microbiologically investigated using a combined culturedependent and-independent approach. Each pedon displayed a generally decreasing level with soil depth for the several microbial groups investigated; in particular, filamentous fungi were below the detection limit at 30–50 cm. To isolate bacteria actively involved in soil particle aggregation, colonies with mucoid appearance were differentiated at the strain level and genetically identified: the major groups were represented by Bacillus and Pseudomonas. MiSeq Illumina analysis identified Actinobacteria and Firmicutes as the main groups. A high microbial variability was found in all the three anthropogenic pedons and the microorganisms constitute a mature community
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Identification and evaluation of antimicrobial resistance of enterococci isolated from raw ewes’ and cows’ milk collected in western Sicily: a preliminary investigation
Full text linkThe present work was carried out to investigate the Antimicrobial Resistance (AMR) of enterococci isolated from raw ewes’ and cows’ milk. The samples were collected from eighteen semi-extensive dairy sheep and cow farms throughout western Sicily. Plate counts, carried out on Rapid Enterococcus Agar commonly used to detect food enterococci, revealed a maximal enterococcal concentration of approximately 4.58 Log Colony Forming Unit (CFU)/mL. Colonies were isolated and differentiated based on genetic analysis by Randomly Amplified Polymorphic DNA (RAPD)-PCR. Thirty-eight different strains were identified. Analysis by a species-specific multiplex PCR assay grouped the strains into three Enterococcus species such as Enterococcus durans, Enterococcus faecalis and Enterococcus faecium. The 38 strains were also investigated for their antimicrobial resistance by a phenotypic approach. All 38 Enterococcus displayed resistance to at least one or more of the antimicrobials tested confirmed that the dairy enterococci could be a vector for the dissemination of antimicrobial resistance. This work showed that enterococci with AMR traits are commonly present in semiextensive dairy sheep and cow farms of western Sicily pointed out the relevance of informing dairy makers and veterinary regarding the antimicrobial use in order to mitigate problems of public health and veterinary medicine
Development of an ad hoc starter culture for the production of functional raw ewes’ milk cheeses through the addition of grape pomace powder
No full textThe present work was carried out to select lactic acid bacteria (LAB) resistant to polyphenols in order to develop an ad hoc starter culture for the production of functional fresh ewes’ milk cheeses through the addition of grape pomace powder (GPP). To this purpose, raw ewes’ milk samples were inoculated with individual polyphenols belonging to five classes: flavanols (cathechin, epicatechin and epigallocathechin), flavonols (quercetin), flavones (rutin), hydroxyl-benzoic acid (vanillic acid and syringic acid) and hydroxyl-cinnamic acid (caffeic acid and cumaric acid). These polyphenols are commonly associated with the wine industry by-products and were added in milk to a final concentration of 0.5 mg/mL. All samples were incubated at 30°C and 44°C for 48h in order to select potential mesophilic and thermophilic starter LAB. Plate counts showed the total microbial counts (TMC) till levels of almost 109 CFU/mL and all milk samples were dominated by coccus LAB. All colonies with different morphological appearance were isolated and differentiated on the basis of their phenotypic characteristics and by Randomly Amplified Polymorphic DNA (RAPD)-PCR profiles. A total of 55 strains were collected and subjected to the genotypic analysis by means of 16S rRNA gene sequencing, which identified 5 LAB species belonging to two genera (Enterococcus and Lactococcus). The species most frequently found were Lactococcus lactis. The 55 strains were investigated in vitro for their general dairy aptitudes and four strains of L. lactis (MISE36, MISE94, MISE169 and MISE190) showed technological traits relevant to act as starter strains for cheese production.In order to produce a GPP-fortified fresh cheeses, red grape pomaces of Nero D’Avola cultivar were provided by a winemaking factory (Cantine Europa, Petrosino, Italy). Grape pomaces were dried at 54°C for 48 h and milled through a Retsch apparatus to a particle size of 250 μm. The experimental cheese making trials were carried out in a dairy pilot plant (Biopek, Gibellina, Italy) following the protocol of “pressed” cheeses. For each trial 20 L of pasteurised milk was divided into two plastic vats (10 L each) representing two different trials. Both vats were inoculated with the individual starter LAB cultures (100 mL) to reach a final cell density of 107 CFU/mL. One vat represented the control cheese (CC) production. The second vat represented the experimental cheese (EC) that, after curd extraction, was added with 1% (w/w) GPP. The cheeses were sampled after one month of ripening. All lactococci were able to perform the rapid acidification in CC and EC production, showing that polyphenols of GPP did not slow down starter development. Plate counts and RAPD analysis applied to the colonies isolated from the highest dilutions of samples confirmed the dominance of the added strains. A sensory evaluation of the resulting cheeses, indicated the cheeses processed with the addition of GPP were well appreciated by the judges. Analyses are in progress to evaluate the nutraceutical properties of the experimental cheeses.
This research has been supported by the grant MISE-2017-NAZ-0228 - CUP: B78I1700026000
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