1,721,054 research outputs found
IMPROVEMENT OF FOOD SAFETY AND MICROBIAL INTERACTIONS
Full text linkIn these studies, different approaches for the conservation of meat and fish products were deepened. The application of bioprotective cultures and the addition of organic salts were investigated, following the current trends of demanding mild technologies for food, in order to contrast the pathogenic and spoilage microorganisms without significant modifications of the sensorial quality of the products.
In the first study, the anti-listerial activity of L. sakei strains, isolated from salmon scraps, was observed evidencing the importance of the possibility to reduce the risk of food alteration in cold smoked salmon industry and to prevent the replication of L. monocytogenes using autochthonous microorganisms with a potential biopreservative action.
Moreover, in the second study, strains of Lactobacillus animalis and L. paracasei subsp. paracasei, never studied before for bioprotective purpose and characterized by limited knowledge regarding their antagonistic properties, showed promising antimicrobial activity in vitro. This action against a wide number of spoilage and pathogenic bacteria was detected both when the strains were used singularly and was more evident when they were applied as mixture (especially when L. paracasei subsp. paracasei was predominant). The antagonistic effect was due mainly to the competition for nutrients and to the production of organic acids (acetic and lactic) as combined effects.
In the third study, two multistrain mixtures (L. sakei mixture and especially L. curvatus mixture), obtained adding different strains isolated and identified from Argentine vacuum packed meat, showed a promising antimicrobial activity against a wide number of spoilage and pathogenic bacteria, highlighting that the antagonistic effect originates probably from the nutrient competitive exclusion and the possible production of metabolites such organic acids. Moreover, the addition of the two mixtures to sliced vacuum-packed beef determined a better microbial quality of meat as TVC, Enterobacteriaceae and Gram negative bacteria resulted lower if compared to control samples. In any case, if compared with in vitro results, a slighter effect was detected on beef samples; it was probably due to the different competitiveness of the cultures if applied to a complex substrate like meat and to the buffering capacity of meat.
The fourth study was focused on the application of organic acids and salts on non-prepacked hamburgers, as they are known to exert potential benefits in terms of bacterial inhibition and stabilization of sensory characteristics. The addition of mixtures containing sodium ascorbate, sodium citrate and sodium acetate was effective in microbial inhibition of non-prepacked beef hamburgers, especially when the highest acetate dose was used. An evident activity was found against Gram negative bacteria, which represent the most important microorganisms in determining the shelf-life of raw minced meat. This, associated with lower TVB-N values, resulted in an improvement in the hygienic quality of treated samples. These salts are now admitted only for “prepacked meat preparations” but the results evidenced the convenience for butchers to extend the use of these organic salts to non-prepacked minced meat preparations as an additional means to ensure product safety and shelf-life.
In conclusion, the two technologies tested in these studies resulted to be promising as an evident antimicrobial effect was confirmed, suggesting the possibility to apply these tools to extend the shelf-life of food
Contenuto di metilmercurio in pesce spada, tonni e selacei : stima dell’esposizione sul consumatore italiano
No full textThanks to a revision of the literature of the period 2000-2013 the mean concentration of methylmercury was obtained in fish species known for their high concentration of the metal such as swordfish (Xiphias gladius), tuna (Thunnus thynnus and Thunnus albacares) and sharks (Prionace glauca, Mustelus mustelus, Isurus oxyrinchus). On the basis of the mean consumption of these species and considering the origin of the fish, the exposure of Italian men and women to methylmercury and the contribution to the Provisional Tolerable Weekly Intake, were estimated. The species caught in the Mediterranean Sea and the Indian Ocean were proved to be the major contributors of methylmercury if compared to those caught in the Atlantic and Pacific Oceans. A correct information for consumers is needed, especially for those belonging to the target populations such as children, pregnant or nursing women, and women of a childbearing age. The consumption of red tuna, swordfish and shark should be limited for these people
Valorizzazione delle carni ovi-caprine
No full textThe report seeks to address a possible way for the promotion of fresh sheepmeat and goatmeat in the European context, through the review of the state of the art of the European market, world market and certification systems such as protected geographical indications (PGI) and designations of protected origin (PDO). The processed sheepmeat and goatmeat products, which have a long tradition in regional kitchens, are also treated; their production is strictly seasonal and addressed to a local consumer, in this national panorama Pitina stands out, the only product to have obtained IGP
Evaluation of the on-chain refrigeration of broiler carcasses on Campylobacter contamination
No full textThermophilic Campylobacters are the first cause of foodborne illness in the European Union (about 230,000 cases in 2015) [1]; it is estimated that about 20-30% of human Campylobacteriosis cases are linked to the consumption of broiler meat [2]. The prevalence of Campylobacters on broiler carcasses after slaughtering is very high [3], due to their wide distribution in the chicken population and to the cross contamination during slaughtering. Campylobacter is not able to grow on the meat surfaces and is gradually inactivated by refrigeration [4], especially when low temperatures are combined with a drying of meat surface, as can be achieved with air-chilling.This study aimed to evaluate the effect of on-chain air chilling on Campylobacter contamination of broiler carcasses in an industrial slaughterhouse. During three sampling sessions (form March to July), a total of 14 slaughtered broiler batches were analyzed as follows:
- Detection of Campylobacter spp. in the caecal content (one pooled sample from 5 caeca for each batch);
- Detection and count of Campylobacter spp. in neck/breast skin samples (3 pools from 10 broiler carcasses for each batch), taken before and after the air refrigeration (4°C for 45 min).
For the analyses, ISO methods were applied, and isolates were identified by PCR. The temperature of the carcasses during the refrigeration (on the surface and under the skin) was also registered. The refrigeration process led to a mean temperature decay of the carcasses of 14.7°C (surface) and 9.1°C (under the skin). All the broiler batches showed the presence of Campylobacters both in caecal content and on carcass surfaces, with about half of the pooled carcass samples having counts >3 Log CFU/g. The refrigeration of the carcasses resulted in a mean decrease of 0.27 Log CFU/g in Campylobacter counts, a slight but statistically significant effect. The main frequency class of counts was higher for pre-refrigeration samples (3-4 Log CFU/g vs 2-3 Log CFU/g). A high correlation was shown between counts pre and post refrigeration, stressing the importance of the previous phases to achieve a low contamination level. Due to the extremely high diffusion of Campylobacters, no differences were detected considering the slaughtering order of the batches or the sampling season. All the isolates belonged to the species C. jejuni or C. coli, with the prevalence of C. jejuni (71%) and of C. coli (86%) in pre and post refrigeration samples, respectively. The application of this chilling step could be useful, in combination with further refrigeration phases (during marketing and storage), in order to achieve constant low counts on broiler meats
Evaluation of effect of chilling steps during slaughtering on the Campylobacter sp. counts on broiler carcasses
Full text linkCampylobacter spp. play an increasing
role as foodborne pathogens, with poultry representing
the main vehicle of infection, and control measures at
the slaughterhouse have been implemented in the last
years. In this study, 2 trials were performed, evaluating
the effect of the chilling phases currently applied in an
industrial slaughterhouse on the Campylobacter sp.
contamination of broiler carcasses. In the first trial,
neck skin samples were taken from 13 flocks before and
after the on-chain air chilling and submitted to analysis
of Campylobacter sp. count; in the second trial, 63
carcasses or cuts stored in the chilling room for variable
times, with or without skin, were submitted to analysis
of Campylobacter sp. count. A selection of 75 isolates
was identified by PCR. All carcass skin samples taken
from the first trial showed Campylobacter sp. counts
higher than 0.7 log cfu/g. A wide variability in the
counts (about 3 logs) was detected, showing a high
correlation between the counts obtained before and
after chilling. A slight decrease (P 5 0.011) was
observed after chilling (mean difference of about 0.3 log
cfu/g), also if variability was observed among the
flocks; the number of samples with high Campylobacter
sp. counts (3 log cfu/g) was reduced (P 5 0.010). In
the second trial, low counts were generally detected
(almost all lower than 3 log cfu/g). An evident
decreasing trend was observed during storage, but the
survival rate of Campylobacter on the cuts with skin
was higher. All the isolates were identified as
Campylobacter jejuni (72%) or Campylobacter coli. The
data obtained were compared with the threshold limit
set by EC Regulation 2073/2005, evidencing the impact
of the sampling point on the counts. Our results highlighted the importance of applying a hurdle strategy
including on-chain chilling and strict respect of the cold
chain, allowing the food business operator to fulfill the
process hygiene criteria and avoiding the delivery of
highly contaminated meat
What happens to the microflora of retail sushi in the warm season?
Full text linkSushi is a perishable ready to eat product composed by several raw ingredients, and the storage temperature is crucial in the maintenance of satisfactory hygiene. Aim of this study was the microbiological characterization of sushi mimicking a thermal abuse likely occurring in the summer season. Mixed sushi (rolls and nigiri) produced in a small scale factory in Northern Italy was stored for 2 h at 12°C (―transport‖) and subsequently for 4 days at 8°C (―home storage‖) and daily submitted to microbiological analyses coupled with the control of organoleptic quality. Total viable Count was above 5 Log since the production day and was mainly constituted by Pseudomonas spp.; the values increased during storage overcoming the 6 Log level from day 3, and reaching level above 8 Log CFU/g at the last sampling time. From a sensorial point of view, from the second day a decay in odour and colour was observed. LAB showed a gradual increase never overcoming 6 Log CFU/g, while Enterobacteriaceae increased and overcame 4 Log CFU/g after 2 days. Yeasts showed a moderate growth (always <5 Log CFU/g) while Bacillus cereus, Staphylococci and Clostridia were generally below the detection limits. Listeria monocytogenes was never detected. A reduction of shelf-life from 3 to 2 days should be applied especially in particular warm months in order to limit bacterial replication
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