349 research outputs found
Authentication of Tokaj Wine (Hungaricum) with the Electronic Tongue and Near Infrared Spectroscopy
Tokaj wines (Hungaricum) are botrytized wines acknowledged for the unique organoleptic properties bestowed by botrytized grape berries during production. Excluding these berries during wine production or manipulating the sugar content of low-grade wines to imitate high-grade wines are some recent suspicious activities that threaten the wine quality. Advanced methods such as spectroscopy and sensor-based devices have been lauded for rapid, reliable, and cost-effective analysis, but there has been no report of their application to monitor grape must concentrate adulteration in botrytized wines. The study aimed to develop models to rapidly discriminate lower grade Tokaj wines, "Forditas I" and "Forditas II," that were artificially adulterated with grape must concentrate to match the sugar content of high-grade Tokaj wines using an electronic tongue (e-tongue) and two near infrared spectrometers (NIRS). Data were evaluated with the following chemometrics: principal component analysis (PCA), discriminant analysis (LDA), partial least square regression (PLSR), and aquaphotomics (a novel approach). There was a noticeable pattern of separation in PCA for all three instruments and 100% classification of adulterated and nonadulterated wines in LDA using the e-tongue. Aquagrams from the aquaphotomics approach showed important water absorption bands capable of being markers of Tokaj wine quality. PLSR models showed coefficient of determination ((RCV)-C-2) of 0.98 (e-tongue), 0.97 (benchtop NIRS), 0.87 (handheld NIRS), and low root mean squared errors of cross-validation. All three instruments could discriminate, classify, and predict grape must concentrate adulteration in Tokaj with a high accuracy and low error. The methods can be applied for routine quality checks of botrytized wines. Practical Application Tokaj wines (Hungaricum) are botrytized wines acknowledged for the unique organoleptic properties bestowed by botrytized grape berries during production. Excluding these berries during wine production or manipulating the sugar content of low-grade wines to imitate high-grade wines are some recent suspicious activities that threaten the wine quality. Using advanced instruments, the electronic tongue, benchtop near infrared spectroscopy, and a handheld near infrared spectroscopy, we could discriminate, classify, and predict grape must concentrate adulteration in Tokaj with a high accuracy and low error. The models in our study can be applied for routine quality checks of botrytized wines
Robustness testing in the determination of seven drugs in animal muscle by liquid chromatographyâtandem mass spectrometry
In this work, the robustness of the sample preparation procedure for the determination of six tranquilizers (xylazine, azaperone, propionylpromazine, chlorpromazine, haloperidol, and azaperol) and a beta-blocker (carazolol) in animal muscle by LC/MSâMS was assessed through the experimental design methodology. A 2III7 â 4 fractional factorial design was performed to evaluate the influence of seven variables on the final concentration of the seven drugs in the samples, in accordance with what is laid down in Commission Decision No 2002/657/EC. The variation considered for each of those seven factors is likely to happen when preparing the samples, being the values chosen as level â 1, the nominal operating conditions. The results of the experimentation were evaluated from different statistical strategies, such as hypothesis testing using an external variance previously estimated, Lenth's method, and Bayesian analysis. Both Lenth's and Bayes' approaches enabled to determine the effect of every variable even though no degrees of freedom were left to estimate the residual error. The same conclusion about the robustness of the extraction step was reached from the three methodologies, namely, none of the seven factors examined influenced on the method performance significantly, so the sample preparation procedure was considered to be robust.Ministerio de
Ciencia e InnovaciĂłn (CTQ2011-26022) and MINECO (CTQ2014-
53157-R)
Lead-free piezoceramics - Where to move on?
Lead-free piezoceramics aiming at replacing the market-dominant lead-based ones have been extensively searched for more than a decade worldwide. Some noteworthy outcomes such as the advent of commercial products for certain applications have been reported, but the goal, i.e., the invention of a lead-free piezocermic, the performance of which is equivalent or even superior to that of PZT-based piezoceramics, does not seem to be fulfilled yet. Nevertheless, the academic effort already seems to be culminated, waiting for a guideline to a future research direction. We believe that a driving force for a restoration of this research field needs to be found elsewhere, for example, intimate collaborations with related industries. For this to be effectively realized, it would be helpful for academic side to understand the interests and demands of the industry side as well as to provide the industry with new scientific insights that would eventually lead to new applications. Therefore, this review covers some of the issues that are to be studied further and deeper, so-to-speak, lessons from the history of piezoceramics, and some technical issues that could be useful in better understanding the industry demands. As well, the efforts made in the industry side will be briefly introduced for the academic people to catch up with the recent trends and to be guided for setting up their future research direction effectively.ope
Broadening Exposure to Socio-Political Opinions via a Pushy Smart Home Device
Motivated by the effects of the filter bubble and echo chamber phenomena on social media, we developed a smart home device, Spkr, that unpredictably âpushesâ socio-political discussion topics into the home. The device utilised trending Twitter discussions, categorised by their socio-political alignment, to present people with a purposefully assorted range of viewpoints. We deployed Spkr in 10 homes for 28 days with a diverse range of participants and interviewed them about their experiences. Our results show that Spkr presents a novel means of combating selective exposure to socio-political issues, providing participants with identifiably diverse viewpoints. Moreover, Spkr acted as a conversational prompt for discussion within the home, initiating collective processes and engaging those who would not often be involved in political discussions. We demonstrate how smart home assistants can be used as a catalyst for provocation by altering and pluralising political discussions within households
Impact of the malaxation temperature on the phenolic profile of cv. Cobrançosa olive oils and assessment of the related health claim
Phenolic compounds contribute to the bioactive properties of olive oil. However, olive oils can only support a health claim concerning the protection against oxidative stress depending on the polyphenolic concentration, requiring effective measures during extraction to preserve/enhance their concentrations. The effect of the malaxation temperature (22, 28 and 34 °C) on the phenolic profile was studied for industrially extracted cv. Cobrançosa oils. Higher malaxation temperatures decreased the contents of the majority of the chromatographically detected compounds (P<0.05, one-way ANOVA), enabling oils differentiation. This decreasing trend was observed for hydroxytyrosol and tyrosol bound forms, determinant for the health claim, which were also negatively affected by temperature, despite revealing that all the industrially extracted oils tested supported the health claim. The observed constant free to bound forms ratio showed that the temperature range tested had a minor effect on bound-forms hydrolysis, being both free and bound forms equally affected by temperature.The authors are grateful to the Foundation for Science andTechnology (FCT, Portugal) forfinancial support by national fundsFCT/MCTES to CIMO (UIDB/00690/2020), to CEB (UIDB/04469/2020), to REQUIMTE-LAQV (UIDB/50006/2020) and to BioTecNorteoperation (NORTEâ01â0145âFEDERâ000004) funded by the EuropeanRegional Development Fund under the scope of Norte2020âPrograma Operacional Regional do Norte. Ătala Marx acknowledges the Ph.D.research grant (SFRH/BD/137283/2018) provided by FCT. NunoRodrigues thanks the National funding by FCT- Foundation for Scienceand Technology, P.I., through the institutional scientific employment program-contract.info:eu-repo/semantics/publishedVersio
Assessing the ecological impacts of invasive species based on their functional responses and abundances
Invasive species management requires allocation of limited resources towards the proactive mitigation of those species that could elicit the highest ecological impacts. However, we lack predictive capacity with respect to the identities and degree of ecological impacts of invasive species. Here, we combine the relative per capita effects and relative field abundances of invader as compared to native species into a new metric, âRelative Impact Potentialâ (RIP), and test whether this metric can reliably predict high impact invaders. This metric tests the impact of invaders relative to the baseline impacts of natives on the broader ecological community. We first derived the functional responses (i.e. per capita effects) of two ecologically damaging invasive fish species in Europe, the Ponto-Caspian round goby (Neogobius melanostomus) and Asian topmouth gudgeon (Pseudorasbora parva), and their native trophic analogues, the bullhead (Cottus gobio; also C. bairdi) and bitterling (Rhodeus amarus), towards several prey species. This establishes the existence and relative strengths of the predator-prey relationships. Then, we derived ecologically comparable field abundance estimates of the invader and native fish from surveys and literature. This establishes the multipliers for the above per capita effects. Despite both predators having known severe detrimental field impacts, their functional responses alone were of modest predictive power in this regard; however, incorporation of their abundances relative to natives into the RIP metric gave high predictive power. We present invader/native RIP biplots that provide an intuitive visualisation of comparisons among the invasive and native species, reflecting the known broad ecological impacts of the invaders. Thus, we provide a mechanistic understanding of invasive species impacts and a predictive tool for use by practitioners, for example, in risk assessments
Contaminant issues in production and application of biochar
For widespread use of biochar in agriculture and horticulture, it must be ensured that
application will neither adversely affect soil and plants, nor exceed legislated
contaminant concentrations. The most relevant groups of contaminants in biochar are
potentially toxic elements (PTEs), polycyclic aromatic hydrocarbons (PAHs) and
volatile organic compounds (VOC). In this thesis, the concentrations of these groups
of contaminants were analysed in 90 different biochars produced by slow pyrolysis.
Subsequently, the concentrations were compared to legislation/guideline threshold
values and linked to production conditions. The risk these contaminants pose to plant
growth was also assessed, to give recommendations on production of safe biochar.
PTEs can neither be formed nor destroyed, which means their presence in biochar is
predominantly determined by feedstock type. However, significant levels of Cr, Fe
and Ni were introduced into biochar from the furnace steel, whilst PTEs with low
boiling points, such as As, Cd and Zn, partially evaporated during pyrolysis. PTEs
were not responsible for phytotoxic effects observed for PTE-rich biochars despite
biocharâs exceedance of available and total PTE threshold values for soil and soil
amendments. Although initial tests were promising, the risk that PTE-rich biochars
as amendment for soil and growing media pose, needs further investigation.
The PAH concentration in biochar was markedly reduced by increasing carrier gas
flow rate, and the type of feedstock also influenced the PAH content. However, there
was no clear dependence of pyrolysis temperature on PAH concentrations, which
was attributed to PAHs being increasingly formed and evaporated at higher pyrolysis
temperatures. Ultimately, condensation of pyrolysis vapours and deposition on
biochar was identified as the main risk for biochar contamination with PAHs, as this
resulted in elevated concentrations of high-risk, higher molecular weight PAHs.
Weaknesses in the pyrolysis unit design, such as cold zones, resulted in elevated
concentrations of VOCs, as well as PAHs, in biochar. Comparing concentrations and
phytotoxic potential of both compound groups, it was concluded that observed toxic
effects were much more likely caused by VOCs in biochars containing both
contaminants. Overall, formation of VOCs and PAHs cannot be prevented, but their
presence in biochar resulting from retention and deposition can be minimised
Constructing a transnational timber legality assurance regime: Architecture, accomplishments, challenges
The emerging transnational timber legality assurance regime comprises a set of interrelated policy instruments, both public and private, aimed at controlling trade in illegally logged wood and wood products. The potentially productive interactions among these instruments in the emerging forestry regime create prospects for engendering learning, stimulating cross-fertilization, and enhancing accountability. In this article, we analyze the EU's Forest Law Enforcement Governance and Trade (FLEGT) initiative, interacting with public legal timber regulations and private certification schemes, as the core of an emerging transnational experimentalist regime. An experimentalist regime of this type may provide a promising approach to addressing contentious transnational environmental issues like forest governance where there is no global hegemon to impose a single set of rules. However, experience with FLEGT implementation suggests that there are also a number of outstanding challenges to constructing an effective timber legality assurance regime, which if unresolved could undermine its promise. The argument proceeds in three steps, based on an exhaustive analysis of recent developments. First, we outline the architecture and promise of the emerging timber legality assurance regime. Then, we review key accomplishments to date. Finally, we examine the ongoing challenges facing this innovative regime as it moves forward, and consider how they might be overcome through the adoption of a more consistent experimentalist approach
Development and assessment of healthy properties of meat and meat products designed as functional foods
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