873 research outputs found
Spoilage of Meat and Fish
No full textMeat and meat products and fish and fish products represent excellent growth media for a large variety of spoilage microorganisms, originating from breeding, fishing, harvesting, preslaughter husbandry practices, and handling during slaughtering, processing, and selling. This microbial population includes psychrotolerant and/or psychrotrophic Gram-negative and Gram-positive bacteria, molds, and yeasts, whose metabolic activity may lead to the production of ammonia, biogenic amines, nonproteic nitrogen compounds, alcohols, ketones, aldehydes, esters, gas (CO2), and other molecules, being responsible of off-odors, off-flavors, discoloration, slime, and swelling of the packages. The storage temperature and the processing technologies may limit or slow down the microbial growth and improve meat and fish shelf life
L'utopia nella storia. Uomini e riviste del Novecento.
No full textUna forte tensione utopica dà impulso all'attività letteraria e all'impegno civile dei protagonisti di questo libro: Giovanni Papini e Giuseppe Antonio Borgese, Girolamo Comi e Carlo Betocchi, Carlo Bo e Mario Apollonio, Giuseppe Dossetti e Primo Mazzolari; uomini per tanti aspetti diversi, ma unanimi nel concepire la loro vocazione intellettuale come una testimonianza che s'incarna nel tempo per gettarvi semi di profezia
Identification and process origin of microorganisms responsible for cavities and volatile off-flavor compounds in artisanal cooked ham
No full textTwo types of spoilage in cooked hams were investigated. One was a result of the growth of Weissella viridescens, which produces cavities in the muscles of hams after cooking. The origin of W. viridescens was shown to be the brine used in the preparation of the ham. After its production, the brine is usually left at room temperature for several hours before being cooled and used, allowing the growth of the microorganism. The second types of spoilage is because of Lactobacillus sakei, Leuconostoc mesenteroides and Leuconostoc carnosum, which grew during the 4-6°C storage period of cooked hams packaged under vacuum. The spoilage consisted of the production of various molecules such as hydrocarbons, aldehydes, ketones, carboxylic acids, alcohols, esters and sulphur compounds. Oxidative and auto-oxidative phenomena also occurred during spoilage
Ecology of moulds during the pre-ripening and ripening of San Daniele dry cured ham.
No full textThe aim of this work was to study the ecology of moulds and their toxic potential during the pre-ripening or ripening of San Daniele dry cured ham. Three different facilities and their products were investigated. These facilities were chosen on the basis of their production capacity: one for industrial production, one for semi-industrial production and one for handicraft production. The mould microflora was predominantly represented by 2 genera, which were found either on the surface of dry cured ham or in the air of the production rooms. The identified species were quite similar among the three facilities. Penicillium spp. and Aspergillus spp. were the main genera isolated during the duration of pre-ripening and ripening. The toxic potential of the isolated strains and the presence of Ochratoxin A (OTA) on the surface of or in San Daniele dry cured ham were also investigated. No OTA was found either on the surface (mould slime) or in the meat of the investigated hams. Moreover, no OTA-producing moulds, with the exception of Aspergillus niger, were isolated. However, different yeast and mould strains were tested for the ability to inhibit the growth of OTA producing moulds. Penicillium nalgiovense, Candida guilliermondii and Endomycopsis fibuliger prevented the growth of co-inoculated OTA producing moulds, and no OTA was detected on the surface of the dry cured ham. Thus, it appears that San Daniele dry cured ham does not represent a health hazar
Microbial quality of raw and ready-to-eat mung bean sprouts produced in Italy
No full textThe aim of this study was to determine the microbial quality of mung bean sprouts produced in Italy. The presence of pathogenic microorganisms (Shiga toxin- producing Escherichia coli (STEC), Salmonella spp. and Listeria monocytogenes), total coliforms, and total viable counts (TVCs) were determined. The study covered five years of sprout production. The results demonstrated that no pathogenic microorganisms were present, and the microbial load was less than 6 log CFU/g. The mung bean sprouts currently produced in Italy were found to be acceptable for consumption. An additional aim was to determine the fate of different strains of STEC, L. monocytogenes and Salmonella spp. by intentionally inoculating mung bean seeds during sprouting and by using chlorinated water to reduce the concentration of these strains in seeds and sprouts. The data demonstrated that these strains increased over 5–6 log CFU/g within 3 days from inocula. The chlorinated washing solution reduced the concentration of the investigated strains in seeds and sprouts by approximately 3 and 7 log CFU/g, respectively. However, it was not possible to completely eliminate the pathogens from either the mung bean seeds or sprouts. Despite these encouraging results, the producer's attention to hygienic quality should not be reduced when attempting to produce safe-to-consume mung bean sprouts
Metodica e relativi primer per l'identificazione di Listeria monocytogenes in substrati organici (alimenti, essudati, urine, sangue)
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