Terpenoids and norisoprenoids in Italian red wines

AIM Terpene compounds are associated with fl oral notes and are characteristic of aromatic grape varieties such as Muscat (Jackson,2008). They are generally considered to potentially contribute to the aroma of white wines. However, there is a growing interesttowards the potential contribution of terpene compounds to the aroma of red wines. The aim of this work was to investigate theoccurrence of diff erent terpenes in red wines from Italian varieties. METHODS For this study wines from 11 mono-varietal Italian redwines from 12 regions were used (19 Sangiovese, 11 Nebbiolo, 10 Aglianico, 11 Primitivo, 10 Raboso del Piave, 9 Cannonau, 11 Teroldego,3 Nerello, 9 Montepulciano, 7 Corvina). All samples were from vintage 2016 and none of them had been in contact with wood. A totalof 19 terpenes and 7 norisoprenoids were analysed by mean of SPME-GC-MS analysis using a DVB-CAR-PDMS fi ber. The wines werecollected in the framework of the activities of the D-Wines (Diversity of Italian wines) project. RESULTS Signifi cant diff erences amongvarieties were observed for basically all the compounds analyzed with the exception of limonene. Overall, the concentrations of thevarious terpenes remained in the same order of magnitude. However, some diff erences are noticeable between varieties. Corvina wascharacterized by higher level of linalool, followed by Aglianico, Nebbiolo, Primitivo and Sangiovese. Cyclic terpenoids appeared asgood varietal markers, for instances Montepulciano was characterized by 1,4-cineole and 1,8-cineole, whereas Sangiovese showedhigher levels of p-cymene, \u3b1-terpinene and 1,4-cineole. Higher terpinene-1-ol content was characteristic of Montepulciano and Rabosowines. Relatively high levels of the norisoprenoid \u3b2-damascenone were found in Cannonau up to 3.68 \u3bcg/L. CONCLUSIONS This studyprovide the fi rst survey of a large number of terpenoids and norisoprenoids in diff erent mono-varietal Italian red wines. The resultsshowed that a large number of terpenoids were present in Italian red wines with specifi c profi les related to the varieties

Differences in the Volatile Profile of Apple Cider Fermented with Schizosaccharomyces pombe and Schizosaccharomyces japonicus

In this study, two strains of Schizosaccharomyces pombe (NCAIM Y01474(T) and SBPS) and two strains of Schizosaccharomyces japonicus (DBVPG 6274(T), M23B) were investigated for their capacity to ferment apple juice and influence the volatile compounds of cider compared to Saccharomyces cerevisiae EC1118. The ethanol tolerance and deacidification capacity of Schizosaccharomyces yeasts could make them potential substitutes for the commonly used S. cerevisiae starter cultures. Despite different time courses (10-30 d), all strains could complete the fermentation process, and Schizosaccharomyces strains reduced the concentration of malic acid in the apple juice. Results indicated that each yeast exerted a distinctive impact on the volatile profile of the apple cider, giving final products separated using a principal component analysis. The volatile composition of the cider exhibited significant differences in the concentration of alcohols, esters, and fatty acids. Particularly, the flocculant strain S. japonicus M23B increased the levels of ethyl acetate (315.44 +/- 73.07 mg/L), isoamyl acetate (5.99 +/- 0.13 mg/L), and isoamyl alcohol (24.77 +/- 15.19 mg/L), while DBVPG 6274(T) incremented the levels of phenyl ethyl alcohol and methionol up to 6.19 +/- 0.51 mg/L and 3.72 +/- 0.71 mg/L, respectively. A large production of terpenes and ethyl esters (e.g., ethyl octanoate) was detected in the cider fermented by S. cerevisiae EC1118. This study demonstrates, for the first time, the possible application of S. japonicus in cider-making to provide products with distinctive aromatic notes"

The impact of some clarifying agents on the precursors of the varietal thiols in juice

3-S-cysteinyl hexan-1-ol (Cys-3MH), 3-S-glutathionyl hexan-1-ol (GSH-3MH) and 4-S-cysteinyl-4-methylpentan-2-one (Cys-4MMP) are precursors of the so-called varietal thiols responsible for the tropical fruity notes produced during fermentation by some yeast strains having lyase activity. A very important step for saving/producing a remarkable level of precursors are grape and juice processing conditions (Larcher et al. 2013). In regards to this, the effects of the main clarifying agents on the content of the quoted precursors are not known up to day. For this reason, 19 juices were produced by direct pressing of white and red grapes according to protocols and with supplements (grape tannin having 224.2 mg/kg GSH-3MH and 25.5 mg/kg Cys-3MH) useful to reach in juice a remarkable level of precursors. These spiked juices, previously cold stabilised and with NTU <20, were treated with high doses (100 g /hL) of bentonite or PVPP or charcoal and cold settled (4°C x 48h), and compared with not spiked juices. Precursors were analysed in the juices using a UHPLC-MS/MS; accurate quantification was guaranteed by deuterated internal standards. Only charcoal caused statistically significant depletion; nevertheless, the changes in percentage terms were limited even with the high dose applied, being roughly 20% for GSH-3MH and 10% for Cys-3MH. No significant differences were found for Cys-4MMP, with a mean depletion due to the clarifying agents < 2% compared to the control treatmen

Fermentative and post-fermentative oxygenation of Corvina red wine: influence on phenolic and volatile composition, colour and wine oxidative response

Background: During the production of red wine, moderate uptake of oxygen in the post-fermentative phase helps the stabilization of colour and the decrease of astringent tannins. However, the influence of oxygen uptake during the fermentative phase in must has not been completely investigated. In this study we evaluated the effect of controlled oxygen supply during fermentation-maceration of Corvina grapes on colour characteristics, tannins, volatile compounds, acetaldehyde production and oxidative stability of the finished wine. Results: Oxygen supply during fermentation improved the formations of stable pigments of Corvina wines due to the higher production of acetaldehyde. However, in wines treated with oxygen a lower production of fruity esters by yeasts was observed. Wines obtained from higher oxygen exposure during fermentation-maceration showed reduced ability to react with oxygen during storage. Conclusions: Fermentative and post-fermentative oxygenation should be considered as a technological approach for modifying colour composition and stability, as well as oxidative behaviour of wine during aging. © 2020 Society of Chemical Industry

Volatile Compounds in Monovarietal Wines of Two Amarone Della Valpolicella Terroirs: Chemical and Sensory Impact of Grape Variety and Origin, Yeast Strain and Spontaneous Fermentation

Aroma profiles of withered Corvina and Corvinone wines from two different Valpolicella terroirs were investigated in relationship to yeast strain and use of spontaneous fermentation. The results indicated that volatile chemical differences between wines were mainly driven by grape origin, which was associated with distinctive compositional profiles. Wine content in terpenes, norisoprenoids, benzenoids and C-6 alcohols, as well as some fermentative esters, were indeed significantly affected by grape origin. Conversely, yeast strain influence was mainly associated with fermentation-derived esters. Sensory analysis, besides confirming the major role of grape origin as driver of wine differentiation, indicated that spontaneous fermentations reduced the sensory differences associated with grape origin and variety, mainly due to high content of acetic acid and ethyl acetate

Oxygen and SO2Consumption of Different Enological Tannins in Relationship to Their Chemical and Electrochemical Characteristics

: The oxidative behavior of five commercial enological tannins of different sources (tea, grape marc, grape seed, untoasted oak, and toasted oak) was investigated in model wine solutions in the presence or absence of SO2. Solutions of the tannins were also analyzed for total phenolics, methyl cellulose precipitable tannins, high-performance liquid chromatography, and linear sweep voltammetry. Tea and oak-derived tannin solutions were characterized by the highest oxygen consumption rates, with oak-derived tannins exhibiting the highest oxygen consumption rates per milligram of phenolic material present. Linear sweep and derivative voltammetry parameters were well-correlated with oxygen consumption rates, whereas total phenolics or total tannins were not. All tannins were associated with consumption of SO2 upon reaction with oxygen, with the lowest rate of SO2 lost per milligram of O2 reacted being observed for oak tannins

Development of a gas chromatography tandem mass spectrometry method for multiple flavours quantification

The chemical study of food and beverage aroma needs nowadays the accurate quantification of an always larger number of flavour compounds from different chemical classes. Generally flavours are analyzed by GC-FID [1] or GC-MS, after a procedure of purification and concentration (SPE, SPME) [2,3]. These two techniques could present low sensibility and selectivity, to avoid this problem, long chromatographic separations were generally proposed with great loss of time [4]. An answer to these problems can be given coupling gaschromatography with a triple quadrupole mass spectrometer (GC-QqQ-MS) configured in multiple reaction monitoring (MRM) mode. Compared to the single quadrupole used in SIM mode, the noise of a triple-quadrupole used in MRM mode is considerably reduced, the sensitivity increased, and the selectivity can be considerably augmented by choosing appropriate transitions. The greater specificity makes possible in many cases to resolve co-eluted peaks even using a less accurate chromatographic separation, and to save time with routine analysis. Flavour compounds were extracted by adsorption on a SPE cartridge (ENV+) [4], eluted with CH2Cl2, concentrated using a Vigreux apparatus and then injected into the GC-MS/MS. The MS/MS parameters, transitions and collision energy, were studied using commercial standards, and their optimization was a compromise between signal intensity and specificity. The developed method permitted ,in wines and spirits, the quantification of 8 acids, 18 alcohols, 39 esters, 13 aldehydes, 10 ketones, 6 phenols, 12 norisoprenoids, 32 terpenols, 11 lactones and 14 sesquiterpens for a total of 163 compounds in only 40 minutes of GC run instead of the classical 90-120 minutes [4]. The number of quantified compounds is definitely higher than many classical routine methods considering also the short time of analysis. The method has shown a satisfactory reproducibility and a good linearity for all the target compounds with R2 higher than 0.99 for all/ almost all compounds. The proposed GC-QqQ-MS method is an important starting point for routine quantitative multiple aroma analysis in complex matrix like wine and spirits because of his rapidness and specificit