50,823 research outputs found
Praedicere Possumus: An Italian web-based application for predictive microbiology to ensure food safety
No full textThe use of predictive modelling tools, which mainly describe the response of microorganisms to a particular set of environmental conditions, may contribute to a better understanding of microbial behaviour in foods. In this paper, a tertiary model, in the form of a readily available and userfriendly web-based application Praedicere Possumus (PP) is presented with research examples from our laboratories. Through the PP application, users have access to different modules, which apply a set of published models considered reliable for determining the compliance of a food product with EU safety criteria and for optimising processing throughout the identification of critical control points. The application pivots around a growth/no-growth boundary model, coupled with a growth model, and includes thermal and non-thermal inactivation models. Integrated functionalities, such as the fractional contribution of each inhibitory factor to growth probability (f) and the time evolution of the growth probability (Pt), have also been included. The PP application is expected to assist food industry and food safety authorities in their common commitment towards the improvement of food safety
Functional fish: improving nutrition for the elderly
No full textElder people need highly digestible foods that can also provide health benefits even to those suffering from chronic diseases.
Furthermore, such foods should be palatable as well as familiar for elder consumers. Fish is a high-protein, low-fat food that
potentially provides a range of health promoting effects which may be further improved with suitable approaches in the
production systems. The present mini-review intends to report possible aquaculture interventions to enhance the positive
impact of fish on elder health and to promote its function in terms of prevention and recovery of specific diseases. Some fish
species during their lifespan experience periods of food restrictions that can be mimicked in aquaculture without affecting
fish welfare. Under these circumstances fish can modify the fatty acid profile and increase the use of muscle proteins to fulfill
their energy requirements, by activation of muscle endogenous proteases. Degradation of muscle proteins can enhance their
digestibility and possibly the release of encrypted bioactive peptides, showing a plethora of biological actions, including the
antihypertensive activity. The degree of myofibrillar protein degradation and the fatty acid profile of fish fillet can then be
managed by suitable and sustainable feeding protocols in the context of farming conditions
Tertiary myotubes in postnatal growing pig muscle detected by their myosin isoform composition.
No full textThe postnatal development of skeletal muscles was studied in growing pigs from 8 to 210 d of age. Indirect immunoperoxidase staining of frozen sections of porcine semimembranosus muscle and longissimus muscle revealed a distinct population of small fibers (tertiary myotubes) that were stained specifically by an antibody (anti-NE) selective for the developmental (embryonic and neonatal) isoforms of muscle myosin. At 8 d of age the other larger fibers were already anti-NE negative and differentiated into Types I and II. A gradual decrease in the number of anti-NE positive fibers together with a gradual increase in area of the remaining positive fibers was observed throughout the pigs' growth. These results may indicate that hyperplastic growth does not cease at birth. Possible mechanisms to explain the origin of these tertiary myotubes containing developmental isoforms of myosin are suggested
Growth of Listeria monocytogenes as influenced by viscosity and water activity
No full textThe effects of osmotic stress on Listeria monocytogenes growth parameters was examined in relation to the viscosity of the
growth media. In low-viscosity systems, growth of L. monocytogenes in glucose-supplemented media was comparable to
growth in sucrose-supplemented media. The relative lag time (RLT: the lag time divided by the generation time) responses were
found to increase in the more restrictive water activity conditions. In high-viscosity systems containing polyvinylpyrrolidone
(PVP), growth rate was reduced, whereas lag time showed no discernible modification. Osmotic stress in medium- and highviscosity
media supplemented with glucose resulted in approximately exponential increasing of the RLT values. Thus, the
biological effects of osmotic stress on L. monocytogenes could be affected by the physical properties of the system, such as
viscosity and diffusivity
A simplified modelling approach established to determine the Listeria monocytogenes behaviour during processing and storage of a traditional (Italian) ready-to-eat food in accordance with the European Commission Regulation N 2073/2005
No full textThis paper considers the applications of the European Commission (EC) Regulation N 2073/2005 concerning
Listeria monocytogenes in ready-to-eat (RTE) food products. A simplified modelling approach
(SMA), which is intended for a practical evaluation of the behaviour of the pathogen during processing
and storage of an RTE meat product (Pitina) from traditional producers, was presented. This approach
included a growth/no-growth model, which was developed by using the limits adopted as safety criteria
by the EU, a model based on the gamma concept (GM) and a kinetic three-phase model (TPL). Based on
the findings of the present study, Pitina was incapable of supporting the growth of L. monocytogenes and
the no-growth conditions assessed through the shelf life by the model were confirmed by challenge
testing. When the simplified approach was used to estimate the total pathogen growth relative to the
Pitina multistage process, taking into account the effects of various hurdles, it provided predictions of
L. monocytogenes growth corresponding to the observed data in the inoculation studies. Therefore, this
simplified approach is expected to enable the food producers to identify appropriate processing conditions.
The successfully validated SMA was found sufficiently complex to predict growth responses of
L. monocytogenes in RTE foods, but at the same time easy-to-use for practical processing situations
Changes of bacterial communities of rainbow trout (Oncorhynchus mykiss) at different processing steps in the production of burgers and their storage life enhancement by an acetate-based preservative
No full textFresh trout (Oncorhynchus mykiss) is a healthy and nutritious food which can be used for formulating ready-to-cook fish preparations, such as trout burgers. To investigate the impact of processing and the use of an acetate-based preservative on the spoilage microbiota and storage life of burgers, the dynamics of microbial communities were examined by using a combination of culture-dependent/independent techniques, Monte Carlo simulation, and PICRUSt2 analysis. Results of the microbial community analyses showed that most of the taxa of trout were lost during processing into burgers. Along the processing steps, an increase of contamination, with Flavobacterium and Pseudomonas becoming the most relative abundant genera in pulp and burgers, respectively, was observed. The Pseudomonas dynamic pattern was supported by the Monte Carlo simulation, which gave a picture of the bacterial transfer. Verdad® N6, which is a commercially available acetate-rich fermentate, was evaluated as preservative treatment for burgers during their storage life. Pseudomonas dominated the microbial community of stored burgers, irrespective of the treatment. However, their levels were lower in the fermentate-treated samples, which presented Lactobacillus as the second most relative abundant genus. PICRUSt2 analysis showed that Pseudomonas-correlated metabolic pathways of hexitol fermentation were significantly lower at the end of the storage period in burgers supplemented with the fermentate, corroborating Pseudomonas minor contribution to the metabolic activity. In summary, Verdad® N6, through its inhibiting effects on spoilage bacteria is an option for producing burgers with increased storage life
Effetto della carnosina sulla sopravvivenza ai trattamenti con radiazioni ionizzanti di Aeromonas Hydrophila e Salmonella Typhimurium
No full text
Properties of wheat dough at sub-zero temperatures and freeze tolerance of a baker's yeast (Saccharomyces cerevisiae)
No full textDifferential Acquisition of m-Sequences using Recursive Soft Sequential Estimation
No full textIn this contribution a novel sequential estimation method is proposed for the acquisition of -sequences. This sequential estimation method exploits the principle of iterative soft-in-soft-out (SISO) decoding for enhancing the acquisition performance, and that of differential pre-processing for the sake of achieving an enhanced acquisition performance, when communicating over various communication environments. Hence the advocated acquisition arrangement is referred to as the Differential Recursive Soft Sequential Estimation (DRSSE) acquisition scheme. The DRSSE acquisition scheme exhibits a low complexity, which is similar to that of an -sequence generator, while achieving an acquisition time that is linearly dependent on the number of stages in the -sequence generator. A low acquisition time is achieved with the advent of the property that the proposed DRSSE scheme is capable of determining the real-time reliabilities associated with the decision concerning a set of, say , consecutive chips. This set of consecutive chips constitutes the sufficient initial condition for enabling the local -sequence generator to produce a synchronized local despreading -sequence replica. Owing to these attractive characteristics, the DRSSE acquisition scheme constitutes a promising initial synchronization scheme for acquisition of long -sequences, when communicating over various propagation environments
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