Determination of pyrethroids in chicken egg samples: development and validation of a confirmatory analytical method by gas chromatography/mass spectrometry

The aim of this study was to develop and validate an efficient analytical method based on gas chromatography/tandem mass spectrometry (GC/MS/MS) for detection and quantification of six pyrethroids residues (Phenothrin, Permethrin, Cyfluthrin, Cypermethrin, Deltamethrin and Fenvalerate) in chicken eggs. The method was based on a preliminary liquid–liquid extraction of albumen‐free yolk samples, followed by a clean‐up by solid‐phase extraction. GC/MS/MS analyses were carried out in the selected reaction monitoring mode. Validation parameters such as specificity, detection capability, decision limit, precision, recovery, stability and ruggedness were determined, resulting in compliance with Decision 2002/657/EC. No complicated apparatus are required; moreover, low volumes of organic solvents and a nonintensive manual labour are required. These low costs and simple procedure, based on rapid and safe operations, may represent a useful tool in the routine analysis of pyrethroids pesticides, in the place of the currently used conventional techniques.     

A comprehensive meta-analysis on evidence of Mediterranean diet and cardiovascular disease: Are individual components equal?

Many studies have reported that higher adherence to Mediterranean diet may decrease cardiovascular disease (CVD) incidence and mortality. We performed a meta-analysis to explore the association in prospective studies and randomized control trials (RCTs) between Mediterranean diet adherence and CVD incidence and mortality. The PubMed database was searched up to June 2014. A total of 17 studies were extracted and 11 qualified for the quantitative analysis. Individuals in the highest quantile of adherence to the diet had lower incidence [relative risk (RR): 0.76, 95% confidence intervals (CI): 0.68, 0.83] and mortality (RR: 0.76, 95% CI: 0.68, 0.83) from CVD compared to those least adherent. A significant reduction of risk was found also for coronary heart disease (CHD) (RR: 0.72, 95% CI: 0.60, 0.86), myocardial infarction (MI) (RR: 0.67; 95% CI: 0.54, 0.83), and stroke (RR: 0.76; 95% CI: 0.60, 0.96) incidence. Pooled analyses of individual components of the diet revealed that the protective effects of the diet appear to be most attributable to olive oil, fruits, vegetables, and legumes. An average reduced risk of 40% for the aforementioned outcomes has been retrieved when pooling results of RCTs. A Mediterranean dietary pattern is associated with lower risks of CVD incidence and mortality, including CHD and MI. The relative effects of specific food groups should be further investigated.     

Structure–composition relationships of the traditional balsamic vinegar of Modena close to jamming transition (part II): Threshold control parameters

The Traditional Balsamic Vinegar of Modena (TBVM) is a high-valuable Italian specialty that, for reasons not yet fully explained, may undergo non-equilibrium degrading phenomena involving phase separation and flow arrest caused by solidification with or without crystalline order. TBVM was probed for its microstructure and composition as well as for its flow ability under low- and high shear limits. Results indicated vinegar concentration, temperature and viscosity as three independent variables affecting the extent of solidification in TBVM. Polymer-mediated mechanisms and diffusion-limited kinetics were hypothesized for structure development. Three main experimental evidences offered a convincing proof unifying all solidification phenomena observed in TBVM under the concept of colloidal jamming transition: (i) simultaneous presence of fractal-like aggregated colloids and polydispersed biopolymers; (ii) non-linear shear dependence above a critical level of vinegar concentration; (iii) a modified Krieger–Dougherty model satisfactorily described scaling behavior of relative viscosity accounting for the fractal dimension of jammed structure. Threshold for jamming in TBVM was defined in terms of critical concentration of the overall structure-active constituents (corresponding to 72°Bx and 40% w/w of the main sugars) and maximum resistance to the Newtonian flow (the onset for shear-thinning flow was achieved with a low-shear limiting viscosity of about 0.95 Pa·s).     

Visual evaluation of cattle cleanliness and correlation to carcass microbial contamination during slaughtering

The aim of the study was to establish whether the visual cleanliness of cattle slaughtered was correlated to hide and carcass contamination as indicated by aerobic colony count (ACC), Enterobacteriaceae count (EC) and Escherichia coli count (ECC). Cattle in a slaughterhouse were visually inspected and assigned to a category from 1 (very clean) to 5 (very dirty) based on cleanliness. Fifteen animals for each category were randomly selected, hide and carcass sampled and analyzed for ACC, EC and ECC. Results showed that increasing dirt on cattle was associated with higher ACC, EC and ECC on hide and carcasses. Carcass ACC and ECC belonging to animals classified in cleanliness categories 3, 4 or 5 have a higher probability of exceeding the limits set by the Reg. EU 2073/2005. The study supports the conclusion that the pre-slaughter visual evaluation of animal cleanliness and application of corrective actions can be an effective aid to reduce carcass contamination.     

Rheological properties and baking quality of commercial durum wheat meals used to make flat crispy bread

Four commercial semolinas and four low-grade semolinas (LGS) samples were used in this study to make flat crispy bread (Carasau). The meals, doughs, and bread were compared with respect to a set of physical, chemical, and textural characteristics, and the bread evaluated by a trained sensory panel. LGSs had a higher extraction rate (higher ash content), finer granularity, and a higher damaged starch content than semolinas. The study revealed the key role of dry gluten content in determining hydration capacity of the dough, whereas damaged starch affected water absorption only in semolina samples. Gluten index and the ratio of gluten tenacity to extensibility (alveograph P/L) were significantly correlated with the weight of the dough discs following sheeting and molding. The panelists gave the highest quality score to the bread with the highest values of crackling and hardness. Textural and sensory attributes were both correlated with one another, and with gluten strength and tenacity, but not with the gluten content of the meal, which only affected final moisture content of the bread. Meal samples with a more tenacious and elastic gluten were more suited to produce flat crispy breads. The yellowness of durum wheat bread could not be predicted by measuring the color of the meal with a reflectance method.     

A PCR-TGGE (Temperature Gradient Gel Electrophoresis) technique to assess differentiation among enological Saccharomyces cerevisiae strains

In this paper new primers, annealing to the ITS2 region, were used to obtain a PCR product that was subsequently subjected to Temperature Gradient Gel Electrophoresis (TGGE) analysis. The PCR-TGGE method performed was able to distinguish Saccharomyces cerevisiae and S. paradoxus and distinguish between strains of S. cerevisiae. Direct analysis of S. cerevisiae and S. paradoxus ecology in musts were also performed.     

Technological activities of Staphylococcus carnosus and Staphylococcus simulans strains isolated from fermented sausages

The aim of this study was to determine the technological properties of 2 strains of Staphylococcus simulans (Ssm12, Ssm21) and 4 strains of S. carnosus (SC28, SC31, SC54 and SC55) for the selection of a potential starter cultures to employ in the processing of dry fermented sausages. The strains were studied to evaluate nitrate reductase, proteolytic, lipolytic, decarboxylase and antioxidant activities as well as growth ability at different temperatures, pH and NaCl concentrations. Nitrate reductase activity was determined at 15, 20 and 30 °C. By spectrophotometric method all the strains were able to reduce nitrate to nitrite at the different temperatures but these results were not confirmed by the agar plate method. Antioxidant and lipolytic activities were evaluated by spectrophotometric assay. All the strains showed antioxidative enzymes superoxide dismutase (SOD) and catalase whereas all appeared unable to hydrolyse pork fat. Proteolytic activity was determined by agar plate method, spectrophotometric assay (OPA) and sodium dodecyl sulphate gel-electrophoresis (SDS–PAGE) and all strains appeared to be able to hydrolyse sarcoplasmic proteins but not myofibrillar proteins. Finally, all the strains grew at 15 and 20 °C, in presence of 10%, 15% and 20% of NaCl and at pH 5.0 and 5.5 and were unable to produce histamine, cadaverine and putrescine. The results showed that all strains studied possess useful technological activities that would make them eligible as a good starter cultures for fermented sausages.     

Juice of New citrus hybrids (Citrus clementina Hort. ex Tan.×C. sinensis L. Osbeck) as a source of natural antioxidants

Fruit juices of pigmented and non-pigmented new citrus hybrids obtained by crossing clementine cv. Oroval with different cultivars of blood oranges were analysed to determine parameters related to fruit quality (total soluble solids titratable acidity, pH), and the content of ascorbic acid, total phenolics, flavanones, anthocyanins and phenolic acids. Antioxidant properties were evaluated by oxygen radical absorbance capacity (ORAC), and inhibition of induced linoleic acid peroxidation (InLAP) assays. The results of this study show that some hybrids with high antioxidant activity owing to considerable polyphenol content may be considered rich sources of phytochemicals. The OTA 9 hybrid was shown to be richest in polyphenols, suggesting that consumption of OTA 9 fruit or juice could be useful in health promotion and a disease-preventing diet. Moreover, the juice of this hybrid could be used as raw material to produce antioxidant ingredients for dietary, pharmaceutical, or cosmetic purposes.     

Lactic acid bacteria ecology of three traditional fermented sausages produced in the North of Italy as determined by molecular methods

In this study the bacterial biodiversity during the maturation process of three traditional sausages produced in the North of Italy (Salame bergamasco, Salame cremonese and Salame mantovano) was investigated by using culture-dependent and -independent methods. Eleven plants, in the three provinces considered here, were selected because starter cultures were never used in the production. The bacterial ecology, as determined by plate counts, was dominated by lactic acid bacteria (LAB), with minor contribution of coagulase negative cocci and yeasts. After molecular identification of 486 LAB strains, the species more frequently isolated were Lactobacillus sakei and Lactobacillus curvatus. This evidence was also confirmed by PCR-Denaturing Gradient Gel Electrophoresis (DGGE). All the samples analyzed were characterized by the constant presence of L. sakei and L. curvatus bands. A richer biodiversity was only detected at the beginning of maturation. The results obtained by the molecular characterization of the L. sakei and L. curvatus and by the cluster analysis of the DGGE profiles highlighted a plant-specific population, rather than a geographic characterization of the products, underlining how the environmental and processing conditions are able to select specific microbiota responsible for the main transformations during the fermentation and ripening of the sausages.