Avoiding nonsense in electronic taste sensing

Altres ajuts: M. del Valle thanks the support from program ICREA AcademiaLast years have watched the birth and profusion of analytical systems known as "taste sensors" or "electronic tongues". Regardless of the fancy names, these "taste sensors" and "electronic tongues" are primarily analytical instruments and require responsible handling and application in order to provide for meaningful results. In spite of intensively reported scientific activities and even commercial availability of such devices, multisensor systems are still not widely used in routine laboratory and industrial practice but are rather research instruments. The purpose of this report is to critically analyze different aspects of multisensor systems' studies and to highlight problematic issues requiring special attention from the research community to keep staying objective with reported results and declared conclusions

Developing Algorithms and a Mathematical Model for Monitoring the Physiological State of Cattle

This study involved theoretical and experimental research at farms with existing hardware and software. Measurements were conducted with non-invasive methods using special bolus transmitters (smaXtec animal care GmbH, Graz, Austria) developed for cow health monitoring. The boluses were introduced orally into the rumen of the studied cows. Algorithms and mathematical models were constructed for identifying estrus, calving and illnesses, and for monitoring feed and water consumption. Initial data were imported from a standard file, compatible with other applications (CSV table). Additionally, correlations were analyzed between temperature indicators, the rumen pH and the motor activity of the cattle. Illustrations include plots of the main vital factors and the correlated functions, and a screenshot of the software working console. Also included are tables with the results for each cow, the average values and the RMS deviation. The mathematical model developed is a set of algorithms and calculation results. Code for its implementation was written in Matlab R2019b and is attached to this report. This mathematical model may be used to process and interpret data obtained by boluses put into the rumen of animals. Keywords: cattle, rumen acidity, temperature, motor activity, estrus, calvin

Determination of Citric Acid in Urine by Enzymatic Flow Injection System Based on a Novel Microfluidic Chip

AbstractA flow injection analysis (FIA) system with enzymatic detection has been proposed for determination of citric acid in urine using a novel microfluidic chip. A microfluidic device based on PDMS channels is designed and fabricated. To determinate the citric acid concentration in real samples and explore interference factors, three models are established based on different standard solutions of citrate, which are prepared with deionized water, artificial urine and real sample without citrate, respectively. The correlation coefficients of these models are 0.9989, 0.9955 and 0.9976 within the range from 0.1mM to 6mM. Meanwhile, a strong correlation is obtained between the three models (Each R2>0.986) with regression analysis. At last, 20 urine samples are tested and an analysis of the correlation between the results measured by the proposed method and by the capillary electrophoresis method is made. Results indicate that this method looks promising in urine citrate analysis because of its high sensitivity, high selectivity and low consumption of solvent

Independent comparison study of six different electronic tongues applied for pharmaceutical analysis

Electronic tongue technology based on arrays of cross-sensitive chemical sensors and chemometric data processing has attracted a lot of researchers' attention through the last years. Several so far reported applications dealing with pharmaceutical related tasks employed different e-tongue systems to address different objectives. In this situation, it is hard to judge on the benefits and drawbacks of particular e-tongue implementations for R&D in pharmaceutics. The objective of this study was to compare the performance of six different e-tongues applied to the same set of pharmaceutical samples. For this purpose, two commercially available systems (from Insent and AlphaMOS) and four laboratory prototype systems (two potentiometric systems from Warsaw operating in flow and static modes, one potentiometric system from St. Petersburg, one voltammetric system from Barcelona) were employed. The sample set addressed in the study comprised nine different formulations based on caffeine citrate, lactose monohydrate, maltodextrine, saccharin sodium and citric acid in various combinations. To provide for the fair and unbiased comparison, samples were evaluated under blind conditions and data processing from all the systems was performed in a uniform way. Different mathematical methods were applied to judge on similarity of the e-tongues response from the samples. These were principal component analysis (PCA), RV' matrix correlation coefficients and Tuckeŕs congruency coefficients

A tool for general quality assessment of black tea : retail price prediction by an electronic tongue

Retail price of food products is a complex interplay between multiple factors. Overall product quality has got one of the most serious impacts on the price in many situations. In the present study, an artificial sensory system (potentiometric electronic tongue) was employed for the analysis of black tea samples purchased in the retail stores in Spain and Russia. It was possible to relate the response of a potentiometric sensor system with retail prices of various black tea samples by means of partial least squares (PLS) regression. PLS regression models are allowed for the prediction of retail price with mean relative errors of about 15 and 25 % for Spain's tea bags and for loosepacked tea from Russia, respectively. The suggested approach shows a promise for the development of an instrumental analytical technique for regulatory authorities to fight with counterfeits and for commercial purposes to evaluate market spac