Effect of Sequential Inoculation with Non-Saccharomyces and Saccharomyces Yeasts on Riesling Wine Chemical Composition

Abstract

In recent years, studies have reported the positive influence of non-Saccharomyces yeast on wine quality. Many grape varieties under mixed or sequential inoculation show an overall positive effect on aroma enhancement. A potential impact by non-Saccharomyces yeast on volatile and non-volatile compounds should benefit the flavor of Riesling wines. Following this trend, four separate sequential fermentations (using the non-Saccharomyces yeasts Torulaspora delbrueckii, Metschnikowia pulcherrima, Pichia kluyveri, and Lachancea thermotolerans with Saccharomyces cerevisiae) were carried out on Riesling must and compared to a pure culture of S. cerevisiae. Sequential fermentations influenced the final wine aroma. Significant differences were found in esters, acetates, higher alcohols, fatty acids, and low volatile sulfur compounds between the different trials. Other parameters, including the production of non-volatile compounds, showed significant differences. This fermentation process not only allows the modulation of wine aroma but also chemical parameters such as glycerol, ethanol, alcohol, acidity, or fermentation by-products. These potential benefits of wine diversity should be beneficial to the wine industry.

Influence of Nutrient Supplementation on Torulaspora Delbrueckii Wine Fermentation Aroma

“…Non-Saccharomyces yeasts are interesting for their ability to improve wine aroma complexity [8,33,58]. The total concentrations of higher alcohols observed were lower than the concentrations usually found in wines, i.e., 140-420 mg/L [59,60], but consistent with previous findings from the literature [17,21,34]. Non-Saccharomyces yeasts are usually indicated as being lower producers of higher alcohols than S. cerevisiae [1,7,33].…”

“…All fermentations were conducted in 500 mL Schott-Duran ® bottles following a previous protocol but adapted to the scale [33,34]. Each variant was performed in triplicate.…”

“…The main oenological parameters of juice before fermentation were measured by means of high-performance liquid-liquid chromatography (HPLC) based on a previously reported methodology [35] with the following modifications [34]. Samples were prepared in 1.5 mL vials after centrifugation at 13,000 rpm for 5 min and subsequent dilution to 1:1 with distilled water, and 5 µL was successively injected into an Agilent Technologies 1100 series liquid chromatograph (Agilent Technologies GmbH, Germany) equipped with 2 detectors, a multi-wavelength detector, and a refractive index (RI) detector (Agilent Technologies GmbH, Germany).…”

“…of the resulting wines were evaluated by means of a gas chromatograph (HP 5890 Series II, Hewlett Packard, Palo Alto, California, Estados Unidos) coupled with a mass spectrometry detector (HP 5972 MSD, Hewlett Packard). The analysis was performed based on a previously reported methodology [37] with the following modifications [34]. First, samples needed to be prepared for the extraction: 10 mL of sample, 10 µL of each internal standard, 2 g of sodium chloride (NaCl), and 160 µL of 1,1,2-trichlorotrifluoroethane (Freon 113) were added to a 15 mL tube.…”

Modern Technologies and Their Influence in Fermentation Quality

“…The use of some specific non-Saccharomyces species allow to control and to improve several wine quality parameters [1,12]. The most popular ones are Torulaspora delbrueckii [13], Lachancea thermotolerans [14][15][16], Metschnikowia pulcherrima [12,17], Schizosaccharomyces pombe [18], Hanseniaspora uvarum [10] and Pichia kluyveri [12]. Some groups are studying the microbiota of vineyards and soils to look for other microorganism different from S. cerevisiae able to enhance quality parameters of alcoholic and malolactic fermentation [19].…”