Mass spectrometry fragmentation pattern of coloured flavanol‐anthocyanin and anthocyanin‐flavanol derivatives in aged red wines of Rioja

Background and Aims: During wine ageing, a great variety of reactions take place, resulting in an immense variety of products whose structure sometimes remains unknown. The aim of this work is the study of different fragmentation patterns of flavanol‐anthocyanin derivatives formed along the wine ageing; these patterns are useful for elucidating the different structures of these compounds and other new related ones. Methods and Results: Several wines from the Protected Denomination of Origin Rioja have been studied by an analytical method that combines column chromatography and high‐performance liquid chromatography with diode array and mass and tandem mass spectrometric detections. Thirty‐five coloured flavanol‐anthocyanin compounds formed by direct reaction or by acetaldehyde‐mediated condensation have been identified. For direct reaction derivatives, two different fragmentation patterns (one of them not previously reported) have been observed depending on the position of flavanol in the coloured derivative. Several compounds have been identified in aged wines for the first time to the authors' knowledge, like (+)‐gallocatechin‐cyanidin‐3‐glucoside and (+)‐catechin‐cyanidin‐3‐glucoside Conclusions: The developed analytical procedure has allowed the identification of some compounds for the first time, and two different fragmentation patterns have been observed depending on the position of flavanol in the pigment. Significance of the Study: The establishment of different fragmentation patterns allows the structural elucidation of unknown compounds.     

Microbial characterisation and stability of a farmhouse natural fermented milk from Spain

This work reports the microbial characterisation of a farmhouse natural fermented milk (NFM) with good sensorial properties produced in Spain. Culturing and denaturing gradient gel electrophoresis (DGGE) analyses showed thatLactococcus lactissubsp.lactis and L. lactissubsp.cremoris(approximate levels of 10⁹ cfu/mL) were dominant in this NFM, whileLactobacillus plantarumappeared at a lower level (10⁶–10⁷ cfu/mL). Repetitive extragenic palindromic (REP)‐PCR typing of the isolates identified single strains each ofLc. lactissubsp.lactis, Lc. lactissubsp.cremorisandLb. plantarum. These three strains formed a stable microbial association which has been maintained for at least some decades.     

EVALUATION OF A SHAPE IDENTIFICATION SYSTEM BASED ON A SIGNATURE FUNCTION

One of the commonest problems in artificial vision is how to identify an object by comparing its characteristics with those of the models included in the recognition system database. Relevant characteristics include properties both of the object's surface (size, shape, and reflectivity) and of its edges. In general, the solution to the problem depends (1) on the type of illumination used and whether its distribution across the scene is uniform or not and (2) on the surface characteristics (reflectivity, texture) of both the object and the background. In this first phase of research we have tried out a particular signature function: the distance of all points on the object's border from the object's center.     

PROBABILISTIC MODELS FOR MONITORING AND FAULT DIAGNOSIS: APPLICATION AND EVALUATION IN A MOBILE ROBOT

This paper presents a general approach for building a robust and efficient supervision system for fault detection and recovery. The approach uses a set of monitors that obtain information about the system state and, instead of detecting fault states directly, detects significant differences between perceived and expected states. To deal with uncertainty in the knowledge about the system state and the result of some actions, it uses a POMDP model to decide when it is worthwhile to take recovery actions. We present the general approach and show its application with an indoor mobile robot by reporting and evaluating comparative results for different solutions.     

Effect of cerium additive and secondary phase analysis on Ag<Subscript>0.5</Subscript>Bi<Subscript>0.5</Subscript>TiO<Subscript>3</Subscript> ceramics

Cerium-doped silver bismuth titanate—Ag_0.5Bi_0.5TiO₃ (ABT) ceramics have been synthesized by the high-temperature solid-state reaction method. The structure and elemental examination of the prepared ceramic was analysed by X-ray diffraction (XRD), Fourier transform infrared, scanning electron microscopy and energy-dispersive spectroscopy. XRD analysis showed the presence of pyrochlore structure and secondary phase when more than 5 mol% cerium was added. The impact of temperature on cerium-doped silver bismuth titanate samples was analysed by differential thermal analysis and differential scanning calorimetry. Cerium doping caused the flaky morphology comparing with undoped sample. The homogeneity of all the samples was discussed in detail by diffuse reflectance spectrum. This is the first time the reflection process is analysed for the cerium-doped ABT system to the best of our knowledge.