New comprehensive procedure for enhanced dataanalysis and interpretation of Real-Time Measurements: A unique feature for real time avour generation

info:eu-repo/semantics/publishedVersio

Nor-isoprenoids profile during port wine ageing—influence of some technological parameters

Nor-isoprenoid compounds, such as β-damascenone, β-ionone, 2,2,6-trimethylcyclohexanone (TCH), 1,1,6-trimethyl-1,2-dihydronaphthalene (TDN) and vitispirane were determined in 14 young port wines and 45 old port wines. As between the two groups of wines levels of these compounds are quite different, an experimental protocol was performed in order to determine which technological parameter (dissolved O2, free SO2 levels, pH and time/temperature) was related with the formation/consumption of these molecules. The five nor-isoprenoids were equally affected by the selected parameters and a similar profile with time was observed. The synergistic effects of increasing temperature and lowering pH had the largest impact. For samples treated with high oxygen regimes (saturation), the levels of all considered nor-isoprenoids decreased after a certain concentration of oxygen consumed (e.g. 10 mg l−1). Nevertheless, during barrel port wine ageing, corresponding to the 45 wines, two different behaviours can be observed: TDN, vitispirane and TCH increase significantly whilst a decrease of levels of β-ionone and β-damascenone with port barrel ageing was observed. It was also calculated that “over 40 year” old port wines have, respectively, 15, 5 and 3 times higher levels of TDN, vitispirane and TCH than the young ports. For these three compounds the respective rates of formation are higher than those of degradation, which suggests a higher number or higher concentration of precursors than those involved for the megastigame C13 nor-isoprenoids β-damascenone and β-ionone

Process control in flavour generation : NIR-MVA as a tool to monitor key odorants formation

info:eu-repo/semantics/publishedVersio

(Un)targeted analysis to unravel critical interactions between sugars and phenolics in Strecker aldehydes formation in beverages

info:eu-repo/semantics/publishedVersio

Simultaneous determination of ketoacids and dicarbonyl compounds, key Maillard intermediates on the generation of aged wine aroma

The aim of thiswork was the simultaneous determination of both ketoacids and dicarbonyl compounds in wine.Todetect ketoacidcompoundsin wine,amethodbasedonthequinoxaline derivativesby the reaction with diaminobenzene, currently employed to detectα-dicarbonyl compounds, was developed. The quinoxaline derivatives were detected by RP-HPLC with UV detection, which allows the determination of the major dicarbonyl compounds in wine: glyoxal, methylglyoxal, diacetyl and pentane-2,6-dione, and the quinoxaline/quinoxalinol derivatives of α-keto-γ-(methylthio)butyric acid and β-phenylpyruvic acid (intermediate ketoacid compounds of methional and phenylacetaldehyde) were simultaneously detected by a fluorescence detector. The identification was performed by comparison with standards and also by using LC-MSMS. The levels found in 15 wines analyzed (white wines,Madeira wines, and Port wines) diverge according to the type and the age of the wine. The ketoacid compounds ranged from 0.2 to 5.7 mg/L for α-keto-γ-(methylthio)butyric acid and 0.1 to 9.6 mg/L for β-phenylpyruvic acid. The quantities observed for dicarbonyl compounds were similar to those already reported

X-metabolomics : a software tool for dynamic mass spectroscopy automated signal processing

One of the major challenges of today's biotechnology is to be able to obtain the maximum of metabolic information for the holistic interpretation of biological systems. Herein we present a new computational application for gas-chromatography mass spectroscopy automated signal processing, named 'X-Metabolomics', that shows to be a potential framework for dynamic systems as fermentation processes interpretation by compounds and pathways identification and quantification and moreover for new metabolites discovery. Our GC-MS signal processing pipeline is implemented into an X-window interface using Tcl/Tk interface and based on R statistical programming environment for comprehensive statistical computing of results and access to 'Bioconductor' bioinformatics platform under Unix, Linux and MacOS. This approach focuses on the robustness of peak extraction algorithms for further identification, quantification and biological interpretation by multivariate analysis, evolving the following steps: i) peaks extraction; ii) supervised filtering; iii) identification of candidate fragments and removal of possible contaminants; iv) compounds identification/quantification; v) compounds expression and co-expression in time-course; and vi) sample classification and biological interpretation by multivariate analysis. 'X-Metabolomics' can be an useful tool in different fields such as pharmacology, genetics, living cells systems, promising to be innovative and very helpful for new drug discovery and new advances in dynamic systems understanding

Do bioactive carotenoids contribute to the color of edible mushrooms?

Carotenoids are biologically active phytochemicals present as micro-components in fruits and vegetables, being responsible for their yellow, orange and red colors. The chromatographic behavior and the UV absorption spectrum provided by HPLC-DAD analysis constitute the clues for their identification. Mushrooms are of increasing importance in modern nutrition and medicine, due to the presence of metabolites with pharmacological potential. In this work, samples of wild and commercial mushroom species (Agaricus bisporus, Amanita caesarea, Amanita rubescens, Boletus edulis, Cantharellus cibarius, Fistulina hepatica, Hydnum rufescens, Hygrophorus agathosmus, Pholiota nameko, Pleurotus ostreatus, Russula cyanoxantha, Suillus bellini, Suillus bovinus, Suillus granulatus, Suillus luteus, Tricholoma equestre and Tricholoma portentosum) were screened by HPLC-DAD for the presence of carotenoids. By applying this methodology to 22 samples, comprising either lyophilized or fresh materials, only β-carotene was found and just in C. cibarius species. The occurrence of this pigment in other three of the analyzed species previously described raises some questions about the methodology used.info:eu-repo/semantics/publishedVersio