Impact of Grape Variety, Yeast and Malolactic Fermentation on Volatile Compounds and Fourier Transform Infrared Spectra in Red Wines

Abstract

Volatile compounds are very important to the flavour and quality of the wine. The study aimed to determine the effect of grape variety (Rondo and Zweigelt), yeast, malolactic fermentation (MLF) and yeast×MLF interaction on the content of volatile compounds in red wines. The wines were produced by sequential inoculation with five commercial yeast strains and a commercial lactic acid bacteria (LAB) strain (induced malolactic fermentation) as well as by inoculation with five commercial yeast strains and without LAB inoculation (spontaneous malolactic fermentation). The volatile compounds were determined by headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME-GC/MS). Forty-six volatile compounds belonging to alcohols, esters, acids, aldehydes, ketones, furan compounds, sulfur compounds and volatile phenols were identified in the wines. The grape variety was the factor with a significant impact on the highest number of volatile compounds, 32 out of 46. Furthermore, 7 compounds were affected by yeast, 10 by MLF and only 3 by yeast×MLF interaction. Characteristic bands in Fourier transform infrared (FTIR) spectra were assigned to the vibrations of functional groups of volatile compounds. The whole FTIR spectra were analysed in detail; three characteristic spectral ranges such as 3650-2700, 1750-1500, and below 1500 cm -1 were shown for different classes of volatile compounds. The most remarkable spectral changes were observed for the last two areas.

Authentication of Polish Red Wines Produced from Zweigelt and Rondo Grape Varieties Based on Volatile Compounds Analysis in Combination with Machine Learning Algorithms: Hotrienol as a Marker of the Zweigelt Variety

“…Wines R1–R5 contained diethyl-2-hydroxybutanedioate (diethyl malate), while R1LAB–5LAB did not contain this compound. Our results regarding the relative content of ethyl lactate in wines subjected to different types of MLF are in agreement with the results of Abrahamse and Bartowsky [ 45 ], Costello et al [ 46 ], Lasik-Kurdyś et al [ 47 ], Malherbe et al [ 48 ] and our previous research [ 38 ]. All these authors state that ethyl lactate is a characteristic volatile product of MLF.…”

“…All these authors state that ethyl lactate is a characteristic volatile product of MLF. Also, the results of the analysis of butyrolactone and 2-phenylethyl acetate conducted in this present study are similar to our previous findings [ 38 ]. In contrast to our study, Abrahamse and Bartowsky [ 45 ] reported that the concentration of 2-phenylethyl acetate was higher in wine subjected to spontaneous MLF compared to induced MLF.…”

“…The Rondo wines were characterized by a high relative contents of the alcohols 3-methylbutan-1-ol, 2-phenylethanol and 2-methylpropan-1-ol, the esters ethyl 2-hydroxypropanoate, ethyl octanoate and diethyl butanedioate, octanoic, acetic and hexanoic acids, the ketone 4-methyl-3-penten-2-one, the terpenes ( E )-6,10-dimethyl-5,9-undecadien-2-one (geranylacetone) and ( Z )-linalool oxide, as well as benzaldehyde and dihydrofuran-2(3H)-one. The main compounds in individual classes of volatiles were the same as in our previous papers [ 38 , 39 , 40 ] with the exception of octanoic acid. This compound was the main acid in the present study, while acetic acid was reported as the most abundant acid in our previous papers [ 38 , 40 ].…”

“…The main compounds in individual classes of volatiles were the same as in our previous papers [ 38 , 39 , 40 ] with the exception of octanoic acid. This compound was the main acid in the present study, while acetic acid was reported as the most abundant acid in our previous papers [ 38 , 40 ]. 3-(Methylsulfanyl) propan-1-ol was the only sulfur compound tentatively identified in this study, which is in agreement with our previous papers [ 38 , 40 ] and in contrast with work by Liu et al [ 41 ], in which 2-methyldihydro-3(2H)-thiophenone was the only sulfur compound identified.…”

“…Hotrienol belongs to the class of terpenes. Jurek [ 38 ] identified this terpene as well as several other terpenes, such as linalool, α-terpineol, citronellol, vitispiran and TDN, in Zweigelt wines.…”