Montserrat Riu-Aumatell

Assessment of Volatile and Sensory Profiles between Base and Sparkling Wines

This paper focuses on the study of the volatile, olfactometric, and sensory composition of base wines and their corresponding sparkling wines (14-24 months aging) obtained at semi-industrial scale during three consecutive harvests. The sensory profile of sparkling wine is more complex than that of base wine, with toasty, lactic, sweet, and yeasty notes being described by the panelists and an even sharper increase of these tastes in the cava reserve. On the other hand, during the second fermentation and subsequent aging in contact with lees, some compounds such as acetate and ethyl esters decrease in amount while others such as norisoprenoids, acetal, diacetyl, and furans appear or increase over time. These volatile compounds could be responsible for the sensory profile depending on their notes, as determined by sniffing. The differences in volatile composition are responsible for the changes observed in the sensory profile of cava with respect to base wine.

Characterisation of volatile composition of white salsify (Tragopogon porrifolius L.) by headspace solid-phase microextraction (HS-SPME) and simultaneous distillation–extraction (SDE) coupled to GC–MS

Two analytical procedures were applied, HS-SPME and SDE, coupled to GC-MS to analyse the volatile composition of white salsify. More than 80 of volatile compounds which belonged to distinct chemical families were analysed. SDE led to the identification of mainly high molecular weight sesquiterpenes, acids and esters. Given that SDE involves high temperatures, heat-sensitive compounds may undergo chemical alteration or artefacts may appear. Results obtained show that SPME was useful for the analysis of alcohols and hydrocarbons of low molecular weight and high volatility that are involved in the characteristic volatile profile of salsify and its sensory perception.

Kinetics of browning, phenolics, and 5-hydroxymethylfurfural in commercial sparkling wines.

We analyzed the degree of browning (absorbance at 420 nm), the phenolics, and the 5-hydroxymethylfurfural (5-HMF) content in six sparkling wines series kept at three temperatures (4, 16, and 20 °C) for over 2 years. Caffeic acid, trans-coutaric acid, p-coumaric acid, and 5-HMF were the compounds with the greatest correlation with browning and time. 5-HMF was the only compound that evolved linearly at all temperatures. We propose that 5-HMF is a better time-temperature marker than the A₄₂₀ parameter or phenolics, because it shows higher linearity with time at all temperatures, is more sensitive to temperature changes, and has lower variability. The kinetics of 5-HMF was studied showing a zero-order behavior. We propose mathematical models that wineries can use to predict the browning shelf life of their sparkling wines as a function of the storage time and temperature.

Identification of 5-hydroxymethyl-2-furfural (5-HMF) in Cava sparkling wines by LC-DAD-MS/MS and NMR spectrometry.

The aim of this study was to elucidate the structure of a potential ageing marker for Cava sparkling wine. In order to clarify the structure of this compound, NMR spectroscopy and hyphenated UHPLC-DAD-MS/MS techniques were used. We identified the hitherto unknown compound as 5-hydroxymethyl-2-furfuraldehyde (5-HMF). This is the first time that this compound has been reported in sparkling wines. A survey, based on the analysis of 80 commercial sparkling wines, showed that 5-HMF is present between 0.25 and 12.81 mg/L, and is compared with those reported for other types of wine. Hypothetical origin of 5-HMF in Cava sparkling wine is discussed.

Ultrahigh-Performance Liquid Chromatography (UHPLC)-Tandem Mass Spectrometry (MS/MS) Quantification of Nine Target Indoles in Sparkling Wines.

An ultrahigh-performance liquid chromatography (UHPLC)-tandem mass spectrometry (MS/MS) method was developed for the simultaneous determination of nine target indoles in sparkling wines. The proposed method requires minimal sample pretreatment, and its performance parameters (accuracy, repeatability, LOD, and matrix effect) indicate that it is suitable for routine analysis. Four indoles were found at detectable levels in commercial Cava samples: 5-methoxytryptophol (5MTL), tryptophan (TRP), tryptophan ethyl ester (TEE), and N-acetylserotonin (NSER). Two of them, NSER and 5MTL, are reported here for the first time in sparkling wines, with values of 0.3-2 and 0.29-29.2 μg/L, respectively. In the same samples, the contents of melatonin (MEL), serotonin (SER), 5-hydroxytryptophan (5-OHTRP), 5-hydroxyindole-3-acetic acid (5OHIA), and 5-methoxy-3-indoleacetic acid (5MIA) were all below the corresponding limits of detection.

Changes in RNA catabolites of sparkling wines during the biological aging.

In this study the catabolites derived from RNA degradation were assessed in Cava sparkling wines as a consequence of lees autolysis. For this purpose, the changes in the content of adenosine, guanosine, inosine, uridine, hypoxanthine, xanthine, and uric acid were determined by UHPLC-MS/MS, in sparkling wines produced on industrial scale, and aged for 4 years. Uridine is the main nucleoside, and its content increases whenever lees cells are present (sur lie aging). Purines seem to have a fermentative origin, with xanthine the most abundant one. When RNA catabolite amounts in sparkling wines aged with or without lees are compared over time, it can be concluded that lees and their cell degradation play an important role in the evolution of Cava; when lees are removed, RNA catabolite amounts remain unchanged.