1,720,979 research outputs found
An Overview of the Application of Blue Light-Emitting Diodes as a Non-Thermic Green Technology for Microbial Inactivation in the Food Sector
Get PDFBlue light is an emerging technology used for the decontamination of food contact surfaces and products. It is based on the activation of photosensitizers by light, determining the release of reactive oxygen species (ROS). ROS causes damage to bacterial cells leading to cell death. Several types of microbes may be treated, such as bacteria, yeasts, moulds and viruses, in planktonic or biofilm form. Blue light technology is affected by several factors: light parameters (i.e., irradiance, dose, wavelength), microbial parameters (i.e., pH, temperature, initial inoculum, grade of biofilm maturation) and surface parameters (i.e., material, roughness, and optical properties). In addition, it may be used alone or coupled with other technologies. The use of blue light shows several advantages, such as safety for food operators, and a lower release of chemicals in the environment. Moreover, it seems unlikely for bacteria to develop resistance to the blue light application
Antimicrobial effect of oxidative technologies in food processing: an overview
No full textHealthy foods with fresh-like appearances are nowadays demanded by consumers. To satisfy these requirements, the research has been focused on unconventional non-thermal technologies; particularly, in this paper, oxidative technologies (ozone, cold plasma, and ionization) are reviewed. The principles underlying their mechanisms of working, generation methods, and antimicrobial activity are revised. Thanks to their ability to explain a very strong oxidative activity, the effect on microbial reduction has been resulted promising, representing a good starting point for the application in the food industry as alternative technologies for sanitization. Thus, an overview of the application of these technologies in the different food categories is done. Particularly, it has resulted that for the application of ionization technology on food, the research is still in the early stages
Biogenic amines in parmigiano reggiano cheese [Presenza di amine biogene nel formaggio parmigiano reggiano]
No full textThe presence of biogenic amines in foods is of prima rv importance because of the impact that these compounds can have on the health of consumers when they are found in high quantities Potentially, cheeses can be affected by the presence of biogenic amines since they are famed following the microbial decarboxylation of amino acids that accumulate during ripening. The aim of this work was to undertake a screening of the biogenic omines present in Parmigiano Reggiano cheese, a cheese characterized by a long ripening period, during which a great number ofprecursas amino acids are formed. Very low contents of biogenic amines were found in all the samples analyzed. In any cose the biogenic amine amounts were much lower than the values considered potentially hazardous fa the health of consumers. The biogenic amine present in a more significant amount was Histomine. The content of biogenic amines was also law in cheese aged fa along time and it was not possible to establish a correlation between the presence of these substances and the ripening time
Textural and sensorial characterisation of Montasio cheese produced using proteolytic starters
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Turbidimetric definition of growth limits in probiotic Lactobacillus strains from the perspective of an adaptation strategy
No full textThe application of an adaptation strategy for probiotics, which may improve their stress tolerance, requires the identification of the growth range for each parameter tested. In this study, 4 probiotics (Lactobacillus acidophilus, Lacticaseibacillus casei, Lacticaseibacillus rhamnosus, and Lactiplantibacillus plantarum) were grown under different pH, NaCl, and sucrose concentrations at 25°C, 30°C, and 37°C. Turbidimetric growth curves were carried out and lag phase duration, maximum growth rate, and amplitude (i.e., the difference between initial and stationary phase optical density) were estimated. Moreover, cell morphology was observed, and cell length measured. The growth response, as well as the morphological changes, were quite different within the 4 species. The L. acidophilus was the most sensitive strain, whereas L. plantarum was shown to better tolerate a wide range of stressful conditions. Frequently, morphological changes occurred when the growth curve was delayed. Based on the results, ranges of environmental parameters are proposed that can be considered suboptimal for each strain, and therefore could be tested. The quantitative evaluation of the growth kinetics as well as the morphological observation of the cells can constitute useful support to the choice of the parameters to be used in an adaptation strategy, notwithstanding the need to verify the effect on viability both in model systems and in foods
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Effetto di innesti proteolitici sulle caratteristiche reologiche di formaggio Montasio
No full textMontasio is a typical Italian hard cheese, produced in the Friuli region from raw milk, using natural starters, and sold either as a table cheese after 60 days' ripening, or in grated form after ≥12 months ripening. As part of a study designed to improve the general quality of the cheese, the effect of the proteolytic starter strains on the ripening process and rheological and sensory characteristics was determined. 106 lactococcal strains were isolated from natural starters, of which 4 ( Enterococcus spp.) with marked proteolytic properties were selected. 3 cheesemaking trials were carried out, using a natural starter (control) or a starter made from pasteurized milk with a mixture of the enterococci, added either at the beginnning of the starter preparation or after incubating for 3 h at 43 oC. After ripening for 60 days, the cheeses were analysed for rheological (texture profile analysis, elasticity, Kramer cell test) and sensory (colour, taste, taste persistence) characteristics. Considerable differences between the 3 batches were observed, the cheese from the incubated starter giving the best overall results
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