Dino Miraglia

Use of starter cultures of dairy origin in the production of Salame nostrano, an Italian dry-cured sausage

The aim of this study was the evaluation of the use of selected lactic acid bacteria (LAB) starter culture of dairy origin in the production of low-acid fermented sausages (Salame nostrano) produced in a small-scale plant in Umbria (Italy), and their effect on microbiological, physico-chemical and sensorial properties of the products. Salame nostrano was obtained with two different technological processes: with and without the addition of selected LAB starter cultures. Microbial counts of safety indicators were lower in salami made with the addition of starter cultures. Pathogens after the first week of ripening were only detected from salami made without the addition of starter cultures. Control salami were rated as paler and harder, whereas those made with the addition of starter cultures as slightly saltier, juicier and in general more acceptable. Selected dairy-origin starter (SDS) cultures did prevent the growth of safety indicators, greatly reduced the rate of isolation of pathogens and increased the acceptability of full-ripened salami.

Seroprevalence and Risk Factors for Toxoplasma gondii Infection on Finishing Swine Reared in the Umbria Region, Central Italy

Toxoplasma gondii is a worldwide zoonotic protozoan parasite and pork is considered the major meat source of Toxoplasma infection in humans. To determine the prevalence of infection of Toxoplasma gondii in pigs reared in the Umbria Region (Central Italy), blood samples of 960 pigs from 10 different farms (96 for each farm) were randomly collected and tested for antibodies (IgG) against T. gondii using an IFA assay. Sera were screened at 1/16 titrr and the endpoint titre was determined. Farm management questionnaires were completed and used to develop descriptive statistics on the tested farms as well as to determine measures of association for risk factors for the presence of T. gondii‐seropositive pigs. A total of 155 seropositive pigs (16.14%) were identified; within herds prevalence ranged from 8.33 to 25%. The statistical analysis identified all‐in‐all‐out housing and cleaning method as risk factors for Toxoplasma infection.

Seroprevalence of Toxoplasma gondii in wild boars (Sus scrofa) from Central Italy

Wild and farmed game meat consumption has been highlighted as an emerging risk factor for Toxoplasma gondii infection in humans. In Central Italy wild boar is widely distributed and is also one of the most popular game species. The main goal of the present study was to estimate the seroprevalence of T. gondii antibodies through a serological survey conducted on 400 hunted wild boars (250 males and 150 females) during three subsequent hunting seasons (2009–2011), using an Immunofluorescence Antibody Assay. The animals were sorted by age, determined on the evaluation of the dental table; 101 were <1 year old, 175 from 1 to 3 years, and 124 > 3 years. Antibodies against T. gondii were detected in 56 (14%) serum samples with titers ranging from 40 to ≥160; a significant association (p < 0.05) was found between seropositivity and age, but not gender, hunting districts, or year of sampling.

Characterization of muscle fibre type and evaluation of the presence of giant fibres in two meat chicken hybrids

Giant fibres are muscle fibres characterized by peculiar traits when observed under a light microscope. They are usually rounded in shape, larger than normal fibres and stain darker when coloured with haematoxylin-eosin. Giant fibres were first studied by Cassens et al. (1969) and since then various authors have taken them into consideration, especially in swine where there seemed to be a connection between their presence and the PSE condition (Fazarinc et al., 2002; Severini and Loschi, 1997). This topic has recently also been considered in turkeys and chicken (Remignon et al., 2000; Mammoli et al., 2004). The aim of this study is to evaluate the muscle fibre distribution and the possible presence of giant fibres in two meat chicken hybrids characterized by different growth speeds.

Comparison Between Carcass Microbial Load Recovered by Swabbing Surfaces of Different Size and Using the Reference Excision Method

The Commission Decision of 8 June 2001 (Commission Decision 2001/471/EC), points out that the non-destructive carcass sampling method only removes a limited amount (often 20% or less) of the total flora present on carcass surfaces and suggests covering at least 100 cm2 per sampling site. Nevertheless, some authors have found similar results on sampling areas smaller than those suggested and when using the excision method (Gill and Jones, 2000). The aim of this study is to evaluate whether a reduction in the area sampled using the non-destructive method could influence the number of bacteria recovered from carcass surfaces in comparison with the excision method. This also takes into consideration the recommendation of the Italian Ministry of Health (Note of the Italian Ministry of Health, 2002) of a reduction in the sampling surface to 25 cm2 when sampling carcasses of 65 kg of live weight or less using the non-destructive method.

Prevalence of Campylobacter jejuni and Campylobacter coli in Chicken Hybrids with Different Growth Rates, Reared According to Conventional and “Free-Range” Production Methods

Miraglia D., Ranucci D., Branciari R., Cioffi A., Mammoli R., Cenci Goga B.T. and Avellini P., 2007. Prevalence of Campylobacter jejuni and Campylobacter coli in chicken hybrids with different growth rates, reared according to conventional and “Free-Range” production methods. Veterinary Research Communications, 31(Suppl. 1), 381–384

Effect of dietary treatment with olive oil by-product (olive cake) on physico-chemical, sensory and microbial characteristics of beef during storage

Several studies have demonstrated that the use of natural preservatives through animal diets could increase the shelf life of meat and meat products since many plant-derived substances show antioxidant and antimicrobial properties. The aim of this work was to study the effect of olive cake dietary supplementation on beef oxidative stability and antimicrobial activity during storage. Beef cattle were randomly divided into three homogeneous groups that were assigned to one of the three diets: a commercial unified based diet administered for 90 days until slaughter (CTR), CTR diet supplemented with 0.5% olive cake administered for 90 days until slaughter (OC1), and CTR diet supplemented with 0.5% olive cake and administered for 60 days followed by the administration of the CTR diet for 30 days until slaughter (OC2). Beefsteaks were overwrapped with oxygen-permeable packaging and analysed at four different storage times (zero, three, six and nine days). At the four sampling times considered from all of the samples, total viable count (TVC), Enterobacteriaceae counts, colour coordinates (CIE L*a*b* colour system), peroxide value (PV), thiobarbituric reactive substances (TBARs) determinations and descriptive sensory analyses were performed. No differences in TVC and Enterobacteriaceae count were detected among the groups over all of the sampling times considered. Differences were recorder among groups for PV, TBARS, colour and sensory analysis. The addition of olive cake in the animal diet had an effect on lipid oxidation reducing the level of PV, TBARS and retarding colour deterioration and the development of off odour in OC meat during storage.

Microbiological characteristics of hamburgers and raw pork sausages, and antibiotic-resistance of isolated bacteria.

D. Ranucci*, D. Miraglia, R. Branciari, V. D’Ovidio and M. SeveriniDepartment of Food Science – Division of Safety and Quality of Food of Animal Origin,University of Perugia, Perugia, Italy*Correspondence: Dipartimento di Scienze degli Alimenti, Sezione di Sicurezza eQualita` degli Alimenti di Origine Animale, Via San Costanzo, 06126 Perugia, ItalyE-mail: ranucci@unipg.it

Identification with multiplex PCR assay of Enterococcus species isolated from dairy products in Umbria, Italy

Enterococci are enteric organisms which are commonly isolated from ewe and goat’s milk production in Umbria, Italy (Cenci Goga et al., 1995; Cenci Goga e Trevisani, 1996). For years enterococci have been considered as microorganisms only indicative of inadequate hygienic practices or exposure of the food to conditions that would permit multiplication of other undesirable bacteria. However, enterococci largely occur in many cheeses, and are now considered to be usual components of their typical microflora. They play a major role in cheese ripening due to lipolytic, proteolytic and caseinolytic activities (Franz et al., 1999). Enterococci have been shown to be only rarely involved in food poisoning outbreaks and only E. faecalis has been demonstrated to cause changes in dairy products, thus being the only species of concern in dairy production (Franz et al., 1999). The aim of this study was to compare a multiplex PCR with the usual protocol performed in our laboratories, based on physiological and biochemical tests, to differentiate E. faecium from E. faecalis.

Differences in chemical, physical and microbiological characteristics of Italian burrata cheeses made in artisanal and industrial plants of Apulia Region

The burrata cheese is a traditional product from Southern Italy, consisting of an envelope of pasta filata (stretched curd) filled with cream and pasta filata strips (usually leftovers from mozzarella production). Physical [water activity (aw), pH], chemical (moisture, NaCl content) and microbiological [total viable count (TVC), Listeria monocytogenes, Salmonella spp., Yersinia enterocolitica, Bacillus cereus, Escherichia coli, Enterobacteriaceae, coagulase-positive staphylococci] characteristics of burrata cheeses manufactured in artisanal and industrial plants were evaluated. The artisanal burrata showed lower aw values in the filling and the final product. The same was recorded in the filling for the moisture, probably due to differences between the types of cream used in the artisanal and the industrial cheesemaking. The pH value of the filling differed between the two groups but no difference was recorded in the final product. Microbiological differences were also recorded, with higher values for TVC and E. coli in artisanal than industrial burrata. All samples were negative for the other microbial determinations, with the exception of coagulase-positive staphylococci and Y. enterocolitica, which were detected in artisanal burrata. Differences in cheesemaking process were probably responsible for the strong variability of the physical and chemical data between the two cheeses; furthermore, differences in the hygienic features were also recorded. Even though artisanal products showed lower aw and pH values and higher NaCl concentration, the higher E. coli loads highlighted the need for a more accurate compliance with hygienic procedures along the artisanal cheesemaking process.