100 research outputs found
Factors Predicting the Intention of Eating an Insect-Based Product
This study provides a framework of the factors predicting the intention of eating an insect-based product. As part of the study, a seminar was carried out to explore how the provision of information about ecological, health, and gastronomic aspects of entomophagy would modify consumer beliefs regarding insects as food. Before and after the informative seminar, two questionnaires about sociodemographic attributes and beliefs about the consumption of insects as food were given. Participants were then asked to carry out a sensory evaluation of two identical bread samples, but one was claimed to be supplemented with insect powder. Results showed that perceived behavioral control is the main predictor of the intention, followed by neophobia and personal insect food rejection. The disgust factor significantly decreased after the participants attended the informative seminar. Sensory scores highlighted that participants gave "insect-labelled" samples higher scores for flavor, texture, and overall liking, nevertheless, participants indicated that they were less likely to use the "insect-labelled" bread in the future. Our findings provide a better understanding of insect food rejection behavior and help to predict the willingness to try insect-based products based on some important individual traits and information
Qualitative and quantitative evaluation of biogenic amines in vitro production by bacteria isolated from ewes' milk cheeses
Studying the production of biogenic amines (BA) by cheese microbiota is important, because high BA concentrations in food represent a health risk for consumers. Qualitative screening with differential media and HPLC quantification were used to investigate the production of 8 BA (2-phenylethylamine, cadaverine, histamine, putrescine, spermidine, spermine, tryptamine, and tyramine) by 72 isolates from curd and cheese samples manufactured with raw and pasteurised ewes' milk. Enterobacteriaceae showed good putrescine and cadaverine production, both for number of positive isolates and for concentrations produced (average: 341 and 785 micrograms/ml, respectively). Among Enterobacteriaceae data are provided on BA formation by Pantoea conspicua, previously not isolated from food samples. All enterococci formed tyramine, often in high amounts (average: 1608 micrograms/ml), and many produced notable 2-phenylethylamine, putrescine, and cadaverine concentrations (average: 184, 121, and 146 micrograms/ml, respectively). BA formation by lactobacilli was overall extremely limited, with the notable exception of high tyramine concentrations produced by 1 Lactobacillus paracasei (800 micrograms/ml) and 2 Lactobacillus curvatus (> 1700 micrograms/ml), all isolated from pasteurised milk samples. Thus, undesired and technologically useful microorganisms both play a role in BA accumulation in cheeses
Biogenic Amines Content of Four Types of "Pecorino" Cheese Manufactured in Tuscany
Biogenic amines content of four types of Tuscan ewes' milk "pecorino" cheese was evaluated using HPLC-UV analysis. All cheeses were manufactured in the same dairy factory with different combinations of milk (raw or pasteurized) and type of ripening. Total biogenic amines and tyramine levels of a raw milk "pecorino" ripened five months, partly in a traditional cave, were significantly higher than those of a pasteurized milk "pecorino" with a similar ripening; and of a two months raw milk "pecorino" ripened in the dairy plant. No statistical significant difference was found when comparing total biogenic amines and tyramine contents of the same five month ripened raw milk "pecorino" with a pasteurized milk "pecorino" ripened six months, partly in a traditional "fossa." In raw milk cave-ripened and "fossa"-ripened cheeses, total biogenic amines exceeded 1000 mg/kg. In cheeses manufactured with raw milk and/or in particular ripening environments, specific hygienic cares are needed to limit biogenic amines form..
Seafood products notifications in the EU Rapid Alert System for Food and Feed (RASFF) database: Data analysis during the period 2011–2015
Short communication: Phenotypic and genetic diversity of wild Lactococcus lactis isolated from traditional Pecorino cheeses of Tuscany
Wild Lactococcus lactis isolates from traditional Pecorino cheeses in 4 regions of Tuscany were isolated and characterized to evaluate the diversity of autochthonous lactococci. Sixty strains of Lactococcus were clustered by the results of carbohydrate utilization and diagnostic enzyme activity. Twenty-one unique strains were then chosen for characterization of salt and temperature tolerance, as well as acidification and proteolytic activity in milk. Genetic analysis of these strains was performed via 16S ribosomal DNA sequencing and multilocus sequence typing (MLST) to elucidate diversity relative to their location of origin. Phylogenetic analysis showed distinct clustering by region within organism subspecies, and phenotypic properties demonstrated concomitant trends. Multilocus sequence typing thus allowed for the regional distinction of isolates separate from those of previous works, supporting the concept that distinctive regional qualities of cheeses are strongly influenced by microbial ecology
Caciotta della Garfagnana cheese: selection and evaluation of autochthonous mesophilic lactic acid bacteria as starter cultures
The aim of this study was to isolate, identify and select, with respect to acidification and proteolytic activities, the autochthonous mesophilic lactic acid bacteria (LAB) present in milk and Caciotta della Garfagnana, a cheese produced either with raw or thermised cow's milk in small dairies and family plants of Garfagnana (Tuscany), to obtain LAB strains with attributes suitable to be employed as starter cultures in this type of cheese, particularly when thermised milk is used to control spoilage microflora. Samples of raw milk, curd and cheese were collected from three representative farmers of the production area and used to isolate autochthonous LAB. Phenotypic and genotypic (species-specific PCR assay) identification of isolated LAB was done. Twenty-eight strains of LAB isolated from milk, curd and cheese were screened for acidifying and proteolytic activities. LAB strains with the better attributes were used as mesophilic starter cultures in technological trials: experimental cheeses manufactured with the addition of autochthonous LAB and control cheeses were compared for LAB and pH evolution. Experimental cheeses presented a significant increase in the mesophilic lactic acid microflora up to 14 days of ripening and significantly lower pH values up to seven days of ripening. The use of wild selected mesophilic lactic acid bacteria, together with thermisation of milk, for the Caciotta della Garfagnana looks very promising and could help to both standardise the production and improve quality and traditional characteristics of this type of cheese
Detection of Mycobacterium avium subsp. paratuberculosis in cheeses from small ruminants in Tuscany
Paratuberculosis is an infectious disease which affects mainly domestic and wild ruminants caused by Mycobacterium avium subsp. paratuberculosis (Map). Map has been associated with human diseases like Crohn disease, type-1 diabetes, sarcoidosis, multiple sclerosis and Hashimoto's thyroiditis. The aim of this study was to determine the level of Map positivity of cheeses produced in Tuscany (Italy) as an indication of human exposure to the specific pathogen. Sampling was focused on artisanal cheeses produced without commercial starter culture from raw sheep or goat milk, on small-scale farms.Samples were tested by quantitative PCR (qPCR) and culture. Map DNA was detected in 4/7 (57.14%) goat, and in 14/25 (56%) sheep cheeses by qPCR, whereas cultivation produced a positive result in only one case. This corresponded to a goat cheese that had also reacted positively by qPCR and yielded a viable Type S (sheep) strain of Map. The Map load of the tested samples based on qPCR ranged from 6Ă—10 to 1.8Ă—104Map cells/g of cheese. The results indicate on average 56.57% and 66.6% positivity of cheese samples and farms, respectively. Hence, the type of cheeses that were analyzed within the context of this study seem to constitute a considerable source of human exposure to Map; although the question remains of whether the Map cells were present in a viable form, since positive results were almost exclusively recorded by qPCR
Microbiological and physicochemical profile of traditional <i>Salsicda toscana</i> during storage
The aim of this study was to evaluate the evolution during refrigerated storage of the main microbiological and physicochemical parameters of a traditional Italian fresh sausage, salsiccia toscana. The following parameters were analyzed at Days 0, 6 and 9 of storage: total aerobic mesophilic and psychrotrophic counts, Brochothrix thermosphacta, lactic acid bacteria, Pseudomonadaceae, Enterobacteriaceae, Escherichia coli, Micrococcaceae, yeasts and moulds, Salmonella spp., Listeria monocytogenes; pH, Aw, moisture, protein, total lipids, ash, fatty acid composition, Thiobarbituric Acid Reactive Substances, colour measurement. The results revealed a statistically significant increase in the main microbiological parameters between Days 0 and 9 of refrigerated storage, with total bacterial counts exceeding 107 CFU/g after nine days and Brochothrix thermosphacta representing the main spoilage microorganism. Among physicochemical parameters, discolouration was noted during the time of storage, with a significantly paler colour on the surface of sausages with casings after nine days of storage. Considering that the initial bacterial counts were higher than 105 CFU/g for Brochothrix thermosphacta, Pseudomonadaceae, lactic acid bacteria and Enterobacteriaceae, and that the product is traditionally purchased loose without any packaging, it is fundamental to improve the good manufacturing practices, particularly measures to control processing temperatures
Staphylococcus aureus growth and enterotoxin production in Italian caciotta cheese
To evaluate growth and enterotoxin production of Staphylococcus aureus in raw milk caciotta, an Italian soft cheese, experimental cheesemaking trials were carried out with and without a commercial starter. Two different inocula of selected enterotoxinproducing S. aureus strains were tested: high (mean value 5.03 log CFU/mL of milk) and low (mean value 3.22 log CFU/mL of milk).
Uninoculated cheeses with milk containing 2.15 log CFU/mL mean value of coagulase-positive staphylococci were also examined. With higher inocul a coagulase-positive staphylococci counts reached 7.57 log CFU/g without starter and had significantly higher values
after the acidification phase than those with starter (below 6.5 log CFU/g). Using an enzyme immunoassay, enterotoxins were detected in cheeses both without and with starter, but the latter showed significantly lower photometrical absorbance values than the former. In low inoculum and uninoculated cheeses without starter, coagulase-positive staphylococci maximum values were between 5 and 6 log CFU/g, without enterotoxin production. To enhance the safety of this cheese it is fundamental to strictly prevent coagulase-positive staphylococci contamination and multiplication, particularly at the primary production level, and to correctly acidify the curd by starter cultures, which can substantially limit total coagulase-positive staphylococci increase
Prevalence, phenotypic and genetic diversity of Campylobacter in poultry fresh meat and poultry products on retail sale in Tuscany (Italy)
In this study, the prevalence of Campylobacter spp. in poultry fresh meat and ready‑to‑cook
products was evaluated. Seventy‑three samples were collected at retail level from
supermarkets and discount stores, obtaining 61.6% positivity. Of 133 Campylobacter isolates,
86 strains (Campylobacter coli, 58.1% and Campylobacter jejuni, 41.9%) were selected for
characterisation on the basis of their SmaI and kpnI pulsed field gel‑electrophoresis (PFGE)
profiles, to exclude clonal replicates. Campylobacters resulted highly resistant to tetracycline,
ciprofloxacin, and nalidixic acid (79.1%, 72.1% and 65.1%, respectively); 50% of C. coli and
13.9% of C. jejuni were resistant to ciprofloxacin and erythromycin, the most important
antimicrobials for human campylobacteriosis therapy. Five C. coli were resistant to 5/7 of
the tested antimicrobials. HS4c was the prevailing C. jejuni serotype group (22.3%), whereas
8 other serotypes were identified in low percentages. SmaI and kpnI profiles showed a
wide variability. The survey showed a high Campylobacter contamination of poultry meat
and poultry products at retail level in Tuscany, Italy. A wide strains’ heterogeneity and a
remarkable level of strains’ antimicrobial resistance have been reported, confirming the need
for an improvement of specific preventive measures along the production chain
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