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Aldehydes are chemicals substances widely distributed in nature and have been quantified in multiple matrices such as air, water, food and beverages. While these compounds with traces can contribute to the fresh aroma of different foods, when used in higher concentrations, they can facilitate the rancidity of foods and the release of taste. However, it is known that several aldehydes are irritating and carcinogenic. In addition, they are considered to be the potential marker for oxidative stress and metabolic status, which has been proposed to estimate cancer disease and symptoms of alcohol abuse. For these reasons, it is essential to establish a method for the determination of aldehydes in different samples. This paper review provides an insight into current knowledge on the methods and applications of aldehyde measurements, with an emphasis on analytical and electroanalytical techniques. Emphasis was put on the reactivity, specificity and toxicity of reactive aldehydes with respect to cellular targets and their concentrations measured in air, food and water. We discuss the different derivatization reagents used to measure aldehydes and their quantification in real matrices for human consumption such as drinking water, orange and apple vinegar, urine, serum, plasma, cigarette smoke, yogurt, and blood samples. [ABSTRACT FROM AUTHOR]

Asthma represents the most common chronic respiratory disease of childhood. Its current standard diagnosis relies on patient history of symptoms and confirmed expiratory airflow limitation. Nevertheless, the spectrum of asthma in clinical presentation is broad, and both symptoms and lung function may not always reflect the underlying airway inflammation, which can be determined by different pathogenetic mechanisms. For these reasons, the identification of objective biomarkers of asthma, which may guide diagnosis, phenotyping, management and treatment is of great clinical utility and might have a role in the development of personalized therapy. The availability of non-invasive methods to study and monitor disease inflammation is of relevance especially in childhood asthma. In this sense, a promising role might be played by the measurement of exhaled biomarkers, such as exhaled nitric oxide (FE(NO)) and molecules in exhaled breath condensate (EBC). Furthermore, recent studies have shown encouraging results with the application of the novel metabolomic approach to the study of exhaled biomarkers. In this paper the existing knowledge in the field of asthma biomarkers, with a special focus on exhaled biomarkers, will be highlighted. [ABSTRACT FROM AUTHOR]

Abstract: It is well known that the substituent effect has a great impact on the reaction mechanism. In this paper, basing on the density functional theory (DFT) method, we have carried out a systematic theoretical study about the reaction of the amino acid anion catalyzed by the aldehyde, where the amino group can react with the aldehyde to produce the imine. Two reaction pathways have been assumed: one is the direct decarboxylation; the other is the intramolecular CO2 transfer. It is found that substituents R 1 (from the amino acid) on the α-carbon of the carboxylate and R 2 (from the aldehyde) adjacent to the Cve crucial influence upon the reaction pathway. When the substituent has π-system, such as Ph, NO2, CN and CO2Et, the decarboxylation is prior to the intramolecular CO2 transfer. On the other hand, when the substituent has not π-system, such as Me, i-Pr, t-Bu, Cl, and OMe, the intramolecular CO2 transfer has an advantage over the decarboxylation. Whichever pathway the reaction proceeds in, electron-withdrawing substituent plays a obvious role in promoting, while the electron-donating substituent has the opposite effect. [Copyright &y& Elsevier]

The article presents a study which examines the effects of 16 aliphatic aldehydes on the production and growth of Penicillium expansum. The study uses filter papers to determine the concentration of patulin in apple juice broths. It also uses real-time polymerase chain reaction to evaluate relative gene expression related to the biosynthesis of patulin in P. expansum. Results show that patulin production and P. expansum growth depends on the presence of double bond and length of carbon chain.

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Copyright of Afyon Kocatepe University Journal of Science is the property of Afyon Kocatepe University, Faculty of Science & Literature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biotechnologie, Agronomie, Societe et Environnement is the property of Les Presses Agronomiques de Gembloux and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)