98 research outputs found

    Rapid assessment of fertilizers manufacturing methods by means of a novel waveguide vector spectrometer

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    This study aims to test the suitability of a waveguide spectrometer, as a rapid and cheap tool to discriminate between different fertilizers according to two different manufacturing methods, such as granulation and blending. The tested instrument is a waveguide vector spectrometer, patented in 2016, that operates in the range 1.6-2.7 GHz, giving both spectral phase and gain measurements. Granulated and blended fertilizers were dehydrated and pulverized to avoid possible interferences due to the water content and the geometry of the sample. The spectral data were analysed by multivariate statistical analysis [principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA)] in order to obtain a discrimination tool considering the whole hidden spectral information. PC1 (95% of the explained variance) and PC2 (4% of the explained variance) are shown to explain most of the spectral variability. A tendency to group samples according to the different production methods can be seen, even if the discrimination is influenced by the different chemical compositions of fertilizers. However, PLS-DA models correctly classified 100% of the samples into granulated and blended classes using spectra obtained by waveguide spectroscopy. Despite being preliminary, the tests carried out on a small number of samples show how the technique coupled with PLS-DA models could be able to discriminate between the analysed fertilizers by means of their spectral signature and according to the manufacturing method, if the chemical composition is kept constant. Further tests are necessary to validate the model, also considering the possibility of grouping fertilizers on the basis of their similar composition

    ASSESSMENT OF THE TOTAL SOLIDS AND FAT CONTENTS IN WHOLE LIQUID EGG PRODUCTS BY ELECTRICAL AND THERMAL CONDUCTIVITY MEASUREMENTS

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    The total solids and fat contents of nine whole liquid egg products were assessed by means of electrical and thermal conductivity measurements. Linear correlations between conductivity values and total solids and fat contents were obtained with R2 values up to 0.995 and 0.990 and maximum errors of predic- 46 TABLE 6 - Linear regression models for the total solids (TS, %) and fat (FC, %) contents estimation from electrical (Ec, mS/cm) and thermal (Tc, W/mK) conductivity measurements. SE: Standard Error. Linear regression equation R2 p-level SE (%) TS=-6.857*Ec+65.373 0.995 0.000 0.27 FC=-4.993*Ec+40.070 0.985 0.000 0.33 TS=-172.967*Tc+109.605 0.992 0.000 0.33 FC=-126.449*Tc+72.521 0.990 0.000 0.27 tion up to 0.41% and 0.42%, respectively. The electrical conductivity of the albumen, yolk and egg mixtures linearly increased with temperature; at 20°C, temperature coefficients of 2.1%/°C, 2.1%/°C and 1.9 %/°C were respectively calculated. On the contrary, the thermal conductivity of the analysed products did not appear to be substantially influenced by the temperature of the liquid

    Estimation of rheological properties of ice cream unfrozen liquid phase by FT-NIR spectroscopy

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    The control of ice cream powder mixture production is carried out evaluating the ice cream liquid phase. The present study was conduced on ice cream and unfrozen liquid phase in order to indirectly evaluate the rheological properties by measuring the powder mixture. The calibration set was formed by samples with different percentage of thickeners, maintaining constant the concentration of the other remaining compounds. After the NIR acquisitions the powders were mixed with warm milk, blended and than settled in order to obtain the unfrozen liquid phase needed for the rheological measurements. For each recipe three batches were prepared. The flow curves were evaluated by using the Ostwald de Waele’s equation and the goodness of fit was evaluated by the R2, which was above 0.95. Predictive models of rheological parameters were set up by means of PLS regressions in order to predict the consistency coefficient (K) and the flow behavior index (n) from spectral acquisitions. High correlation of calibration was found for both parameters and NIR spectra obtaining R2 of 0.884 for K and 0.874 for n. The good prediction of the models encourages applying them to reduce significantly the time of the powder mixing control during production

    Effect of Non-thermal Atmospheric Plasma on Viability and Histamine-Producing Activity of Psychotrophic Bacteria in Mackerel Fillets

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    open5noNon-thermal atmospheric plasma (NTAP) has gained attention as a decontamination and shelf-life extension technology. In this study its effect on psychrotrophic histamine-producing bacteria (HPB) and histamine formation in fish stored at 0–5°C was evaluated. Mackerel filets were artificially inoculated with Morganella psychrotolerans and Photobacterium phosphoreum and exposed to NTAP to evaluate its effect on their viability and the histidine decarboxylase (HDC) activity in broth cultures and the accumulation of histamine in fish samples, stored on melting ice or at fridge temperature (5°C). NTAP treatment was made under wet conditions for 30 min, using a dielectric barrier discharge (DBD) reactor. The voltage output was characterized by a peak-to-peak value of 13.8 kV (fundamental frequency around 12.7 KHz). This treatment resulted in a significant reduction of the number of M. psychrotolerans and P. phosphoreum (≈3 log cfu/cm2) on skin samples that have been prewashed with surfactant (SDS) or SDS and lactic acid. A marked reduction of their histamine-producing potential was also observed in HDC broth incubated at either 20 or 5°C. Lower accumulation of histamine was observed in NTAP-treated mackerel filets that have been inoculated with M. psychrotolerans or P. phosphoreum and pre-washed with either normal saline or SDS solution (0.05% w/v) and stored at 5°C for 10 days. Mean histamine level in treated and control groups for the samples inoculated with either M. psychrotolerans or P. phosphoreum (≈5 log cfu/g) varied from 7 to 32 and from 49 to 66 μg/g, respectively. No synergistic effect of SDS was observed in the challenge test on meat samples. Any detectable amount of histamine was produced in the meat samples held at melting ice temperature (0–2°C) for 7 days. The effects of NTAP on the quality properties of mackerel’s filets were negligible, whereas its effect on the psychrotrophic HPB might be useful when time and environmental conditions are challenging for the cool-keeping capacity throughout the transport/storage period.openTrevisani M.; Cevoli C.; Ragni L.; Cecchini M.; Berardinelli A.Trevisani M.; Cevoli C.; Ragni L.; Cecchini M.; Berardinelli A

    Rapid and innovative instrumental approaches for quality and authenticity of olive oils

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    The quality of virgin olive oils is assessed through the determination of several analytical parameters, whose values must be within the ranges established by the different institutions involved. In addition to official methods, there is a strong need for simple, rapid, and environmentally friendly techniques for the quality control of virgin olive oils and for addressing the challenging task of determining geographical origin and detecting adulterants. Toward this purpose, some of the most interesting applications based on optical spectroscopic techniques, on the measurement of electrical characteristics and on the use of instruments equipped with electronic chemical sensors, including also other promising techniques are herein discussed. These techniques, adequately coupled with an appropriate statistical approach, appear to be promising for assessment of several quality-related parameters. The prediction of sensory attributes and of the oxidative status of virgin olive oils have also been reviewed by adopting these selected techniques, which are also considered to be potentially appropriate solutions for identification of the geographical origin of virgin olive oils and to assess their adulteration with cheaper oils. Overall, the techniques discussed are promising and cutting-edge approaches for the establishment of useful portable instruments for in situ monitoring of the quality of virgin olive oils. Practical applications: The simple, rapid, and environmentally friendly analytical approaches discussed herein represent promising analytical tools for assuring the authenticity and monitoring the quality of virgin olive oils. Such innovative techniques and tools need to be ring-tested and validated. Some innovative reviewed approaches will permit to develop useful portable instruments able to perform in situ appropriate controls also by small laboratories or olive oil mills with limited technical facilities. These equipments will be potentially usable also by trained \u201cnon-professional analytical skilled\u201d people. Some other approaches, rapid but more expensive, will be applicable mainly by quality control labs and will increase the number of samples analyzed per day, thus fostering laboratory proficiency and an effective fighting against olive oil fraud

    Effectiveness of the mechanical excitation applied to the olive paste: possible improving of the oil yield, in malaxation phase, by vibration systems

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    The mechanical vibrations characterized by a frequency lower than 200 Hz could promote the cells breakage and improve the oil extraction process by avoiding, at the same time, the negative effects on the commercial qualitative parameters due to the use of the heating during malaxation. Vibration tests were conducted by means of an electrodynamic shaker in order to find the optimal frequency levels of excitation, able to put in a resonant condition the olive paste. Sinusoidal accelerations at constant acceleration (120 m/s2), in a range between 5 and 200 Hz were explored. The 50 Hz and 80 Hz frequencies were able to put in resonant condition the olive paste. In the vibrated samples at 50 Hz (15 min of treatment), the maximum increment of the extraction efficiency (about 53% in comparison with the control), was observed. Further studies could be conducted in order to assess the synergic effect of the mechanical vibrations and the malaxation on the oil extraction efficiency, with the aim of reducing the time of the whole phase and avoiding changes in the oil quality traits

    Effect of pulsed electric fields pre-treatment on mass transport during the osmotic dehydration of organic kiwifruit

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    [EN] Recently, some authors have applied pulsed electric fields (PEF) as a pre-treatment of osmotic dehydration, showing a faster kinetics of dehydration. Osmotic dehydration of fruit tissue shows complex mass transfer mechanism associated with active and passive transports of the vegetal matrix, usually driven by electrolytes. The aim of this work was to analyze the effect of different PEF values (100, 250, 400 V/cm) as a pre-treatment of the osmotic dehydration (61.5°Brix, up to 120 min) on mass transport mechanism of organic kiwifruit. A thermodynamic model able to describe the mass transfer and tissue deformation in kiwifruit was developed. It was possible to conclude that pulsed electric field as a pre-treatment, remove a part of the native electrolytes, reducing the activity of protein active pumps, leaving alone the passive protein channels as a main mass transmembrane transport and therefore affecting to the regular functionality of cell homeostasis system.The authors Urszula Tylewicz and Marco Dalla Rosa want to thank for the financial support of this project provided by funding bodies within the FP7 ERA-Net CORE Organic Plus, and with cofunds from the European Commission (this project has received funding from the European Union's 7th Framework Programme under grant agreement No 618107.). The author Marta Castro-Giraldez wants to thank the UPV Postdoctoral Program (PAID-10-14) of the Universidad Politecnica de Valencia for its support. The author Maria Victoria Traffano Schiffo wants to thank the FPI Predoctoral Program of the Universidad Politecnica de Valencia for support her PhD studies, ERASMUS PRACTICAS program to finance her mobility to Italy and also Silvia Tappi and Wei Luo for their cooperation during the experiment.Traffano-Schiffo, MV.; Tylewicz, U.; Castro Giraldez, M.; Fito Suñer, PJ.; Ragni, L.; Dalla Rosa, M. (2016). Effect of pulsed electric fields pre-treatment on mass transport during the osmotic dehydration of organic kiwifruit. Innovative Food Science & Emerging Technologies. 38:243-251. https://doi.org/10.1016/j.ifset.2016.10.011S2432513

    A prospective, randomised, controlled clinical study on the assessment of tolerability and of clinical efficacy of Merional (hMG-IBSA) administered subcutaneously versus Merional administered intramuscularly in women undergoing multifollicular ovarian stimulation in an ART programme (IVF)

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    <p>Abstract</p> <p>Background</p> <p>Multifollicular ovarian stimulation (MOS) is widely used in IVF and the compliance to treatment is deeply influenced by the tolerability of the medication(s) used and by the ease of self-administration. This prospective, controlled, randomised, parallel group open label, multicenter, phase III, equivalence study has been aimed to compare the clinical effectiveness (in terms of oocytes obtained) and tolerability of subcutaneous (s.c.) self-administered versus classical intramuscular (i.m.) injections of Merional, a new highly-purified hMG preparation.</p> <p>Methods</p> <p>A total of 168 normogonadotropic women undergoing IVF were enrolled. Among them, 160 achieved pituitary suppression with a GnRH-agonist long protocol and were randomised to MOS treatment with Merional s.c. or i.m. They started MOS with a standard hMG dose between 150–300 IU, depending upon patient's age, and underwent a standard IVF procedure.</p> <p>Results</p> <p>No statistically significant difference in the mean number of collected oocytes (primary endpoint) was observed between the two study subgroups (7.46, SD 4.24 vs. 7.86, SD 4.28 in the s.c. and i.m. subgroups, respectively). As concerns the secondary outcomes, both the pregnancy and the clinical pregnancy rates were comparable between subgroups. The incidence of adverse events was similar in the two groups (2.4% vs. 3.7%, respectively). Pain at injection site was reported only the i.m. group (13.9% of patients).</p> <p>Conclusion</p> <p>Merional may be used by s.c. injections in IVF with an effectiveness in terms of retrieved oocytes that is equivalent to the one obtained with i.m administration and with a better local tolerability. With the limitations due to the sample size af this study, s.c. and i.m. administration routes seem to have the same overall safety.</p

    Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR

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    [EN] Osmotic dehydration (OD) is a widely used preservation technique that consists in the reduction in food water activity by the immersion of the biological tissue in hypertonic solutions. The aim of this work was to analyze the effect of pulsed electric fields (PEF) in mass transfer as a pre-treatment of the OD using NMR. In this sense, PEF pre-treatments were done using three different voltages (100, 250 and 400 V/cm) and 60 number of pulse. The OD of kiwifruit was carried out in 61.5% of sucrose solution at 25 °C, for a contact period from 0 to 120 min. The water distribution into the cellular tissue was studied by NMR relaxometry. In conclusion, NMR is an excellent technique for quantifying water molecules according to their interactions in the fruit tissue, obtaining the adsorbed water and opening the possibility to apply the BET model to fit the adsorbed isotherm over the whole range of water activity.The authors Urszula Tylewicz and Marco Dalla Rosa want to thank for the financial support provided by funding bodies within the FP7 ERA-Net CORE Organic Plus, and with cofounds from the European Commission. The author Maria Victoria Traffano Schiffo wants to thank the FPI Predoctoral Program of the Universidad Politecnica de Valencia for support her PhD studies, ERASMUS PRACTICAS program to finance her mobility to Italy. The authors Pedro J. Fito, Marta Castro-Giraldez and M. Victoria Traffano-Schiffo acknowledge the financial support from the Spanish Ministerio de Economia, Industria y Competitividad, Programa Estatal de I+D+i orientada a los Retos de la Sociedad AGL2016-80643-R.Traffano-Schiffo, MV.; Laghi, L.; Castro Giráldez, M.; Tylewicz, U.; Rocculi, P.; Ragni, L.; Dalla Rosa, M.... (2017). Osmotic dehydration of organic kiwifruit pre-treated by pulsed electric fields and monitored by NMR. Food Chemistry. 236:87-93. https://doi.org/10.1016/j.foodchem.2017.02.046S879323
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