Bdellovibrio bacteriovorus to control Escherichia coli on meat matrices

Bdellovibrio bacteriovorus is a predator micro-organism towards other Gram-negative bacteria. We tested B. bacteriovorus to control Escherichia coli growth on chicken slices and canned beef. Moreover, we analysed B. bacteriovorus's lytic ability on eight toxigenic or multidrug-resistant E. coli strains. In chicken slices, the predator induced the highest prey reduction (4.3 log) respect to control at 6 h. In canned beef, the predator induced the highest prey reduction (2.1 log) respect to control at 6 h. Moreover, B. bacteriovorus showed lytic ability towards all tested E. coli strains. B. bacteriovorus could control E. coli and other pathogenic and spoilage bacteria in those meat-based foods that have a shelf life <10 days. It could integrate modified atmosphere packaging (MAP) to prolong the shelf life and improve the safety of pre-packed fresh meat, meat preparations and meat products. In future applications on meat-based foods, B. bacteriovorus could also minimise the use of additives.     

Evaluation of Functional Phytochemicals in Destoned Virgin Olive Oil

Processing destoned olives by means of extracting adjuvants micronised food talc and depolymerising Cytolase 0 enzyme complex have been studied in the present work. This innovative processing technology increased the plant efficiency (amounts of olives processed per hour) by 20%, as well as the nutritional quality of the end product with respect to functional compounds. The oils showed higher contents of biophenols, aromas, and tocopherols. An intense and balanced flavor and a potentially higher stability and endurance to oxidation (shelf-life) was found. Contents of chloroplast pigments (chlorophylls, pheophytins, carotenes, and xanthophylls) appeared to be lower in comparison to conventional processing. The processing aids allowed to increase significantly the oil yields and to reduce the oil percentage in the byproducts. Traceability of the new products was still possible applying chemometric data analysis for discriminating between cultivars.     

Characterization of Crude Esterase Activity from Two Plants Used in Cheese Making: Cynara cardunculus L. and Ficus carica L.

For centuries, extracts of Cynara cardunculus and the latex of Ficus carica have been used in cheesemaking, thanks to their proteases that clot milk casein. Since esterase activity is important to release odorous compounds in cheese, in this study we characterized the esterase activity of an extract of Cynara cardunculus and the latex of Ficus carica. The results, obtained by titration, spectrophotometric techniques, zymograms, and tests on agar plates, show the presence of esterase activity in the samples tested, with affinity towards the esters of short chain fatty acids, such as acetic, propionic, and butyric acid. In conclusion, this study provides a background information on esterases of two plants used in cheesemaking and represents a starting point for further investigations of their applications, not only in dairying but also in other industries involved in the processing and transformation of lipids.     

Mo.nalis.a: a methodological approach to identify how to meet thermal industrial needs using already available geothermal resources

Mo.nalis.a is a conceptual model aimed at identifying the most suitable local geothermal sources to match the nearest industrial thermal needs. The methodological approach proposed is based on investigating industrial thermal processes and then identifying suitable geothermal solution plants that match these thermal requirements. The model was tested in Apulia (southern Italy) as a case study for assessing how the methodology could contribute to reducing the use of conventional energy resources for the industrial heat supply sector. The medium thermal needs in Apulia are always higher than 60 °C, and the main strategic industrial processes discussed into this work are “pasta and flour production” “wastewater treatment/sludge digestion” and “swimming pool management”. In order to match these industrial thermal demands, the most suitable proposed plant is the ground water heat pump system, limited to the first 100 m, the depth involved in the heat exchange through vertical probes of model. Finally, Mo.nalis.a identifies the Apulian areas with a possible development of these three activities using geothermal resource: the Foggia province, Murge and Salento sectors.     

Fluorescence Polarization Immunoassay for Rapid, Accurate and Sensitive Determination of Ochratoxin A in Wheat

A sensitive and accurate fluorescence polarization (FP) immunoassay has been developed for the determination of ochratoxin A (OTA) in naturally contaminated wheat samples. A fluorescein-labeled OTA tracer was synthesized, and its binding response with three monoclonal antibodies was tested. The most sensitive competitive FP immunoassay showed an IC₅₀ value of 0.48 ng/mL with a negligible cross-reactivity for ochratoxin B (1.7 %) and no cross-reactivity with other mycotoxins commonly occurring in wheat. The wheat sample was extracted with acetonitrile/water (60:40, v/v) and purified by a rapid solid-phase extraction procedure using an aminopropyl column prior to the FP immunoassay. The overall time of analysis was less than 20 min. The average recovery from spiked wheat samples (3 to 10 μg/kg) was 87 %, with relative standard deviations generally lower than 6 %. Limits of detection and quantification were 0.8 and 2.0 μg/kg, respectively. The trueness of the method was assessed by using two reference materials for OTA showing good accuracy and precision. A good correlation (r?=?0.995) was observed between OTA contamination of 19 naturally contaminated wheat samples analyzed by both FP immunoassay and high-performance liquid chromatography/immunoaffinity clean-up used as reference method. These results show that the developed FP method is suitable for high-throughput screening, as well as for reliable quantitative determination of OTA in wheat at level far below the EU regulatory limits.     

The premium price for Italian red wines in new world wine consuming countries: the case of the Russian market

Italian wine is increasingly appreciated in new world consumer countries and, in particular, in Russia where consumers associate its consumption with an Italian lifestyle. In this paper, market value for wine search attributes is measured through the estimation of a hedonic price model using online data from a Wine Searcher website and the information contained in the labels of wines marketed in Russia. Results show a premium price for wines from Piedmont and Tuscany, and in particular for non-native varieties and for Indicazione Geografica Tipica and Protected Geographical Indication wines. Additionally, vintage and higher alcohol content have a significant positive impact on the prices that consumers are willing to pay for wines. The knowledge of the implicit price of wine quality attributes has important implication for producers to aid in the adoption of effective marketing strategies, and for decision-makers for the adoption of effective measures to improve regional competitiveness in the world market.     

Comparison between self-reported and observed food handling behaviors among Latinas

The study was conducted to compare and identify the magnitude of differences between self-reported and observed food safety behaviors among women preparing a chicken and salad dish at home. The observed food safety practices also were compared according to sociodemographic variables and prior food safety education. Sixty Puerto Rican women who were the main meal preparers for their households were recruited in Hartford, Conn. Three household visits were made to (i) deliver food ingredients to prepare the chicken and salad meal, (ii) conduct household observation, and (iii) conduct a self-reported survey. The difference between self-reported and observed behaviors varied across food handling and sanitation behaviors. There was a high level of inaccuracy for socially desirable behaviors such as hand washing; the vast majority of participants reported practicing these behaviors but they were not observed doing so. Cutting board washing also was considerably overreported, questioning the validity of these self-reported data for regression analyses. There was a significant association (P < 0.05) between proper thawing method and prior food safety education, use of cutting board and higher income, and washing tomatoes and having a positive attitude towards food safety. Results revealed that overreporting errors must be considered when analyzing and/or interpreting data derived from self-reported food safety consumer surveys and that food safety education and positive food safety attitudes are associated with recommended food safety behaviors.     

Volatile phenols in virgin olive oils: Influence of olive variety on their formation during fruits storage

The potential significance as odorants and markers of olive fruits degradation has been recently pointed out for volatile phenols in virgin olive oil (VOO) and related to the appearance of VOO sensory defects. The few studies carried out in order to elucidate the factors affecting their formation in olive fruits or VOOs, indicated that they could be considered as analytical indices of olive fruits degradation during storage, likely reflecting the microbiological activity. In the present study, the effect of the olive variety (‘Arbequina’, ‘Arbosana’ and ‘Leccino’) on the production of volatile phenols during twelve days of storage in closed plastic bags was evaluated. The different resistance of each variety to the microbiological attach was observed during olive fruit storage, and it was reflected by the evolution of guaiacol, 4-ethylphenol and 4-ethylguaiacol, and related to free acidity values. On the contrary, a scarce dependence on the microbial growth or varietal factors was observed for 4-vinyl derivatives, which appeared more directly related to the time of olives storage. The evolution of volatile phenols found certain correspondence in the sensory characteristics of the resulting VOOs, while the rest of VOO chemical quality indices did not show major variations during fruits storage.     

Membrane separation technology for the reduction of alcoholic degree of a white model wine

The reduction of the alcoholic degree of a white model wine by means of membrane separation technology was studied in this work. Reverse osmosis and nanofiltration are the most promising processes for the production of wines with low alcohol content, because they can operate at low temperature and thereby preserve the aromatic profile of wine. Assuming that the rejection of the main wine compounds (i.e. acids, sugars and tannins) is very high, the aim of this research was to study the permeation of several characteristic aroma compounds in the white model wine. Permeation was conducted in batch retentate-recycling mode with two reverse osmosis and one nanofiltration membranes previously conditioned with a 12 ml/100 ml aqueous ethanol solution. Aroma compounds were identified by gas chromatography coupled to quadrupolar mass selective spectrometry. A mathematical model allowed calculation of the aroma compound concentrations in the retentate and permeate streams as a function of permeate volume and the concentration of solutes in the diluted final wine at 8 ml/100 ml ethanol concentration.