Application of Fourier-Transform Infrared Spectroscopy for the Assessment of Wine Spoilage Indicators: A Feasibility Study.

Wine aroma is one of the most frequently used and explored quality indicators. Typically, its assessment involves estimating the volatile composition of wine or highly trained assessors conducting sensory analysis. However, current methodologies rely on slow, expensive and complicated analytical procedures.

An NMR-based lipidomic approach to identify Parkinson's disease-stage specific lipoprotein-lipid signatures in plasma.

Disturbances in lipid composition and lipoproteins metabolism can play a crucial role in the pathogenesis of Parkinson's disease (PD) and other neurodegenerative diseases. The lipidomic strategy proposed here involves lipoprotein profiling using NMR spectroscopy and multivariate data pre-processing and analysis tools on 94 plasma samples (belonging to 38 early-stage PD patients, 10 PD-related dementia patients, 23 persons with Alzheimer's dementia, and 23 healthy control subjects) to firstly differentiate PD patients (irrespective of the stage of the disease) from persons with Alzheimer's disease (AD) as well as from controls, and then to discriminate among PD patients according to disease severity. The whole data set was subdivided into 86 training and 8 external test samples for validation purposes.

Thawing as a critical pre-analytical step in the lipidomic profiling of plasma samples: New standardized protocol.

Lipid profiling is a promising tool for the discovery and subsequent identification of biomarkers associated with various diseases. However, data quality is quite dependent on the pre-analytical methods employed. To date, potential confounding factors that may affect lipid metabolite levels after the thawing of plasma for biomarker exploration studies have not been thoroughly evaluated.

Plasma lipidomic profiling method based on ultrasound extraction and liquid chromatography mass spectrometry.

Lipidomics is an emerging field in biomedical research that includes the analysis of all the lipids present in complex biological samples. To evaluate the chemical and biological diversity of lipids, lipid extraction is usually the first step toward lipidomics analysis. Nevertheless, sample preparation is still a time-consuming and error prone analytical step.

Optimisation of a sensitive method based on ultrasound-assisted emulsification-microextraction for the simultaneous determination of haloanisoles and volatile phenols in wine.

In this study, an ultrasound-assisted emulsification-microextraction (USAEME) has been optimised for the sensitive determination of haloanisoles (2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloroanisole (PCA)) and volatile phenols (4-ethylphenol (4-EP), 4-ethylguaiacol (4-EG), 4-vinylphenol (4-VP) and 4-vinylguaiacol (4-VG)) in wine using gas chromatography coupled to tandem mass spectrometry (GC-MS/MS). Optimisation of USAEME method was performed by evaluating the different parameters that influence the recovery of the analytes in the extract. Firstly, extraction solvent was selected.

Development of an ultrasound-assisted emulsification-microextraction method for the determination of the main compounds causing cork taint in wines.

In this work, an ultrasound-assisted emulsification-microextraction method has been optimised for the determination in wine of haloanisoles (2,4,6-trichloranisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and pentachloranisole (PCA)) responsible for the so-called cork taint. Their halophenolic precursors (2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), 2,4,6-tribromophenol (TBP) and pentachlorophenol (PCP)) have also been simultaneously determined. For this purpose, parameters affecting the USAEME-derivatisation procedure were exhaustively investigated.

Headspace solid-phase microextraction for direct determination of volatile phenols in cider.

A headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry (GC-MS/MS) method was optimised and validated for the determination of 4-ethylguaiacol, 4-ethylphenol, 4-vinylguaiacol and 4-vinylphenol, involved in the presence of Brett character, in ciders. The influence of different parameters on extraction efficiency (fibre coating, salt addition, exposure time, extraction temperature and sample volume/total volume ratio) was evaluated. Divinylbenzene/carboxen/PDMS was selected as extraction fibre and the other optimised parameters were as follows: 10 mL of cider, temperature 70 degrees C, extraction time 60 min and addition of 0.

Valorization of onion waste and by-products: MCR-ALS applied to reveal the compositional profiles of alcoholic fermentations of onion juice monitored by near-infrared spectroscopy.

The overall purpose of the project, of which this study is a part, was to examine the feasibility of onion waste as a support-substrate for the profitable production of food-grade products. This study focused on the efficient production of ethanol from worthless onions by transforming the onion juice into onion liquor via alcoholic fermentation with the yeast Saccharomyces cerevisiae. The onion bioethanol produced could be later used as a favorable substrate for acetic fermentation to finally obtain onion vinegar.

Use of near-infrared spectroscopy and feature selection techniques for predicting the caffeine content and roasting color in roasted coffees.

Near-infrared spectroscopy (NIRS), combined with diverse feature selection techniques and multivariate calibration methods, has been used to develop robust and reliable reduced-spectrum regression models based on a few NIR filter sensors for determining two key parameters for the characterization of roasted coffees, which are extremely relevant from a quality assurance standpoint: roasting color and caffeine content. The application of the stepwise orthogonalization of predictors (an "old" technique recently revisited, known by the acronym SELECT) provided notably improved regression models for the two response variables modeled, with root-mean-square errors of the residuals in external prediction (RMSEP) equal to 3.68 and 1.

Monitoring of alcoholic fermentation of onion juice by NIR spectroscopy: valorization of worthless onions.

The valorization of vegetable byproducts is one of the main objectives of industry today. The project on which this study is based examined the potential usefulness of worthless onions (Allium cepa L. sp.

Multiple solid-phase microextraction in a non-equilibrium situation. Application in quantitative analysis of chlorophenols and chloroanisoles related to cork taint in wine.

Multiple HS-solid-phase microextraction (MHS-SPME) is a modification of SPME developed for quantitative analysis that avoids possible matrix effects based on an exhaustive analyte extraction from the sample. In this paper, the theory of this process associated with a non-equilibrium situation has been presented. The application of an optimised HS-SPME-based method in the analysis of chloroanisoles and chlorophenols, previously acetylated, associated with the occurrence of cork taint in different red, white and rosé wine samples, has revealed the existence of matrix effects.

Orthogonal signal correction applied to the classification of wine and molasses vinegar samples by near-infrared spectroscopy. Feasibility study for the detection and quantification of adulterated vinegar samples.

The most common fraudulent practice in the vinegar industry is the addition of alcohol of different origins to the base wine used to produce wine vinegar with the objective of reducing manufacturing costs. The mixture is then sold commercially as genuine wine vinegar, thus constituting a fraud to consumers and an unfair practice with respect to the rest of the vinegar sector. A method based on near-infrared spectroscopy has been developed to discriminate between white wine vinegar and alcohol or molasses vinegar.

Optimisation of a headspace solid-phase microextraction method for the direct determination of chloroanisoles related to cork taint in red wine.

One of the most critical problems in the enological industry is associated with cork taint. The main compounds responsible for this off-flavour are some chloroanisoles: 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TECA) and pentachloroanisole (PCA). Headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-electron capture detection has been used for the direct determination of these chloroanisoles in wine samples.

Optimisation of the derivatisation reaction and subsequent headspace solid-phase microextraction method for the direct determination of chlorophenols in red wine.

An acetylation reaction for the derivatisation of the three chlorophenols involved in cork taint was optimised using a Doehlert design for direct application in wine samples. In this first step, the optimum reaction pH, by adding different amounts of KHCO3, and the required quantity of derivatisation reagent were fixed. Then a series of parameters relevant for the headspace solid-phase microextraction process, such as desorption conditions, salt addition and agitation sample were evaluated.