Has the use of talc an effect on yield and extra virgin olive oil quality?

The maximization of both extraction yield and extra virgin olive oil quality during olive processing are the main objectives of the olive oil industry. As regards extraction yield, it can be improved by both acting on time/temperature of malaxation and using physical coadjuvants. It is well known that, generally, increasing temperature of malaxation gives an increase in oil extraction yield due to a reduction in oily phase viscosity; however, high malaxation temperature can compromise the nutritional and health values of extra virgin olive oil, leading to undesirable effects such as accelerated oxidative process and loss of volatile compounds responsible for oil flavor and fragrance. The addition of physical coadjuvants in olive oil processing during the malaxation phase, not excluded by EC regulations owing to its exclusively physical action, is well known to promote the breakdown of oil/water emulsions and consequently make oil extraction easier, thus increasing the yield. Among physical coadjuvants, micronized natural talc is used for olive oil processing above all for Spanish and Italian olive cultivars. The quality of extra virgin olive oil depends on numerous variables such as olive cultivar, ripeness degree and quality, machines utilized for processing, oil storage conditions, etc. However, the coadjuvants utilized in olive processing can also influence virgin olive oil characteristics. The literature highlights an increase in oil yield by micronized natural talc addition during olive processing, whereas no clear trend was observed as regards the chemical, nutritional and sensory characteristics of extra virgin olive oil. Although an increase in oil stability was reported, no effect of talc was found on the evolution of virgin olive oil quality indices during storage. © 2016 Society of Chemical Industry     

Evolution and perspectives of cultivar identification and traceability from tree to oil and table olives by means of DNA markers

In recent years, an increasing number of typicality marks has been awarded to high‐quality olive oils produced from local cultivars. In this case, quality control requires effective varietal checks of the starting materials. Moreover, accurate cultivar identification is essential in vegetative‐propagated plants distributed by nurseries and is a pre‐requisite to register new cultivars. Food genomics provides many tools for cultivar identification and traceability from tree to oil and table olives. The results of the application of different classes of DNA markers to olive with the purpose of checking cultivar identity and variability of plant material are extensively discussed in this review, with special regard to repeatability issues and polymorphism degree. The characterization of olive germplasm from all countries of the Mediterranean basin and from less studied geographical areas is described and innovative high‐throughput molecular tools to manage reference collections are reviewed. Then the transferability of DNA markers to processed products – virgin olive oils and table olives – is overviewed to point out strengths and weaknesses, with special regard to (i) the influence of processing steps and storage time on the quantity and quality of residual DNA, (ii) recent advances to overcome the bottleneck of DNA extraction from processed products, (iii) factors affecting whole comparability of DNA profiles between fresh plant materials and end‐products, (iv) drawbacks in the analysis of multi‐cultivar versus single‐cultivar end‐products and (v) the potential of quantitative polymerase chain reaction (PCR)‐based techniques. © 2016 Society of Chemical Industry     

Effect of vacuum-packaging storage on the quality level of ripened sausages

To investigate the influence of vacuum-packaging on both the sensory properties and the degradation level of their lipid fraction, some ripened sausages (30 days) were further stored for 40 days under vacuum-packaging and compared to sausages kept unpackaged for the same period of time. The same kind of sausages was used in both the trials. As for the sensory properties, after storage the unpackaged sausages showed significantly higher mean scores of red intensity and global flavour than vacuum-packed ones (p<0.01 and p<0.05, respectively) indicating a brighter red colour of meat and a greater overall appreciation by the panelists. Regarding the degradation of the lipid fraction, significantly higher values (p<0.01) of the free fatty acids were detected in the vacuum-packed samples, indicating a greater hydrolytic degradation of their lipid fraction as compared to the sausages stored unpackaged. The oxidative degradation of the fatty fraction, measured by the combined use of conventional (determination of peroxide value and TBA test) and non-conventional techniques (HPSEC analysis of the polar compounds of the lipid fraction) showed significant increases during storage for both the storage conditions considered but no significant differences were found between packaged and unpackaged sausages.     

Safe immobilization of Cr(III) in heat-treated zeolite tuff compacts

The possibility to remove chromium ions from a simulated electroplating wastewater by a discontinuous ion-exchange process based on phillipsite-rich Neapolitan yellow tuff (NYT) has been investigated. The immobilization of the pollutant cation in the resulting sludge through a heat-treatment has been realized, demonstrating that compacts made of Cr-loaded NYT powder, fired at temperatures of 1000 degrees C or over, are safe materials with negligible Cr3+ leaching. The set up overall process allows, in addition, a volume reduction of the waste with associated lower disposal costs or, better, the obtainment of a ceramic material, whose physical and mechanical properties are comparable to those of similar ordinary ceramics, such as bricks. In summary, the proposed strategy looks at the polluted sludge as a resource to be exploited, instead of a dangerous material to safely dispose of.     

Polycarbonate for frozen stress photoelasticity

The possibility of using polycarbonate in the frozen stress photoelastic technique is investigated. The results obtained from strip specimens made of laminated and extruded polycarbonate and from plates confirm this possibility.     

Exploiting Visual Languages Generation and UML Meta Modeling to Construct Meta-CASE Workbenches

In the paper we propose an approach for the construction of meta-CASE workbenches. The approach is based on the technology of visual language generation systems and on UML meta modeling. Visual modeling environments are generated starting from UML class diagrams specifying abstract syntax of the underlying visual language. The meta-CASE generates a workbench by integrating a set of visual modeling environments through inter-consistency constraints defined on the corresponding UML class diagrams.     

Ultra‐low‐noise large‐bandwidth transimpedance amplifier

Equivalent input current noise and bandwidth are the most relevant parameters qualifying a low‐noise transimpedance amplifier. In the conventional topology consisting of an operational amplifier in a shunt‐shunt configuration, the equivalent input noise decreases as the feedback resistor (R_F), which also sets the gain, increases. Unfortunately, as R_F increases above a few MΩ, as it is required for obtaining high sensitivity, the bandwidth of the system is set by the parasitic capacitance of R_F and reduces as R_F increases. In this paper, we propose a new topology that allows overcoming this limitation by employing a large‐bandwidth voltage amplifier together with a proper modified feedback network for compensating the effect of the parasitic capacitance of the feedback resistance. We experimentally demonstrate, on a prototype circuit, that the proposed approach allows to obtain a bandwidth in excess of 100 kHz and an equivalent input noise of about 4 fA/ , corresponding to the current noise of the 1 GΩ resistor that is part of the feedback network. The new approach allows obtaining larger bandwidth with respect to those obtained in previously proposed configurations with comparable background noise. Copyright © 2014 John Wiley & Sons, Ltd.