The kinetics of oxygen and SO2 consumption by red wines. What do they tell about oxidation mechanisms and about changes in wine composition?

This work seeks to understand the kinetics of O2 and SO2 consumption of air-saturated red wine as a function of its chemical composition, and to describe the chemical changes suffered during the process in relation to the kinetics. Oxygen Consumption Rates (OCRs) are faster with higher copper and epigallocatechin contents and with higher absorbance at 620 nm and slower with higher levels of gallic acid and catechin terminal units in tannins. Acetaldehyde Reactive Polyphenols (ARPs) may be key elements determining OCRs. It is confirmed that SO2 is poorly consumed in the first saturation. Phenylalanine, methionine and maybe, cysteine, seem to be consumed instead. A low SO2 consumption is favoured by low levels of SO2, by a low availability of free SO2 caused by a high anthocyanin/tannin ratio, and by a polyphenolic profile poor in epigallocatechin and rich in catechin-rich tannins. Wines consuming SO2 efficiently consume more epigallocatechin, prodelphinidins and procyanidins

Cross-tolerance to abiotic stresses in halophytes: Application for phytoremediation of organic pollutants

International audienceHalopytes are plants able to tolerate high salt concentrations but no clear definition was retained for them. In literature, there are more studies that showed salt-enhanced tolerance to other abiotic stresses compared to investigations that found enhanced salt tolerance by other abiotic stresses in halophytes. The phenomenon by which a plant resistance to a stress induces resistance to another is referred to as cross-tolerance. In this work, we reviewed cross-tolerance in halophytes at the physiological, biochemical, and molecular levels. A special attention was accorded to the cross-tolerance between salinity and organic pollutants that could allow halophytes a higher potential of xenobiotic phytoremediation in comparison with glycophytes

Test Case Generation of Actor Systems

Testing is a vital part of the software development process. It is even more so in the context of concurrent languages, since due to undesired task interleavings and to unexpected behaviours of the underlying task scheduler, errors can go easily undetected. Test case generation (TCG) is the process of automatically generating test inputs for interesting coverage criteria, which are then applied to the system under test. This paper presents a TCG framework for actor systems, which consists of three main elements, which are the original contributions of this work: (1) a symbolic execution calculus, which allows symbolically executing the program (i.e., executing the program for unknown input data), (2) improved techniques to avoid performing redundant computations during symbolic execution, (3) new termination and coverage criteria, which ensure the termination of symbolic execution and guarantee that the test cases provide the desired degree of code coverage. Finally, our framework has been implemented and evaluated within the aPET system

Test Case Generation by Symbolic Execution: Basic Concepts, a CLP-based Instance, and Actor-based Concurrency

The focus of this tutorial is white-box test case generation (TCG) based on symbolic execution. Symbolic execution consists in executing a program with the contents of its input arguments being symbolic variables rather than concrete values. A symbolic execution tree characterizes the set of execution paths explored during the symbolic execution of a program. Test cases can be then obtained from the successful branches of the tree. The tutorial is split into three parts: (1) The first part overviews the basic techniques used in TCG to ensure termination, handling heap-manipulating programs, achieving compositionality in the process and guiding TCG towards interesting test cases. (2) In the second part, we focus on a particular implementation of the TCG framework in constraint logic programming (CLP). In essense, the imperative object-oriented program under test is automatically transformed into an equivalent executable CLP-translated program. The main advantage of CLP-based TCG is that the standard mechanism of CLP performs symbolic execution for free. The PET system is an open-source software that implements this approach. (3) Finally, in the last part, we study the extension of TCG to actor-based concurrent programs

Identification and quantification of key phytochemicals in peas – Linking compounds with sensory attributes

International audiencePea protein isolates contain high-quality plant protein. However, they have sensory drawbacks, notably bitterness and astringency, that have limited their use in commercial foods. This study's aim was thus to identify the main phytochemicals in pea-based samples and to examine associations with sensory attributes. The phytochemical profiles of pea flour, pea protein isolates, and pea protein isolate fractions were characterized via UHPLC-DAD-MS. Forty-eight phytochemicals were observed: 6 phenolic acids, 5 flavonoids, and 1 saponin were unambiguously identified and quantified, while another 9 phenolic acids, 10 flavonoids, and 6 saponins were tentatively identified. The impacts of protein extraction and fractionation were studied. These processes appear to have caused some compound degradation. It was found that 29 compounds were correlated with perceived bitterness and/or astringency. Therefore, these results show that certain phytochemicals can lead to negative sensory attributes in pea-protein-based products