Effect of Torulaspora delbrueckii Yeast on the Anthocyanin and Flavanol Concentrations of Cabernet franc and Pinotage Wines

Abstract

Pinotage and Cabernet franc grape must were inoculated with Saccharomyces cerevisiae and Torulaspora delbrueckii yeasts. Differences in colour were observed between Pinotage (S. cerevisiae) and Pinotage (T. delbrueckii) wines, whereas differences in berry and herbaceous character were observed between Cabernet franc (S. cerevisiae) and Cabernet franc (T. delbrueckii) wines. Mouthfeel properties between treatments for both wines were not significantly different. Overall quality was slightly higher in wines inoculated with T. delbrueckii compared to wines inoculated with S. cerevisiae. Anthocyanins and flavanols measured in Pinotage wines made with T. delbrueckii were higher compared to Pinotage must inoculated with S. cerevisiae. Cabernet franc wines made with S. cerevisiae were higher in anthocyanin glycoside and flavanol concentrations compared to Cabernet franc wines made with T. delbrueckii. Insignificant differences in acetylated and coumarylated anthocyanins were evident between Cabernet franc (S. cerevisiae) and Cabernet franc (T. delbrueckii) wines. Principal component analysis showed that epigallocatechin gallate, epicatechin gallate, procyanidin B2, peonidin 3-O-glucoside, delphinidin 3-(6-acetyl) glucoside, petunidin 3-(6-acetyl) glucoside, malvidin 3-(6-acetyl) glucoside and malvidin 3-O-glucoside concentrations were highest in Pinotage wines inoculated with T. delbrueckii. Cabernet franc wines inoculated with S. cerevisiae yeasts were highest in malvidin 3-(6-p-coumaroyl) glucoside, petunidin 3-(6-p-coumaroyl) glucoside, petunidin 3-O-glucoside, epicatechin gallate and epigallocatechin gallate concentrations. Total anthocyanins were highest in Pinotage (S. cerevisiae) wines and Cabernet franc (T. delbrueckii) wines. Flavanols were highest in Pinotage (T. delbrueckii) and Cabernet franc (S. cerevisiae) wines. It is evident from the results that yeast species has an impact on the flavonoid concentrations within a grape variety.

Torulaspora delbrueckii Yeast Strains for Small-scale Chenin blanc and Pinotage Vinifications

“…Wines produced from the T. delbrueckii strain M2/1 treatment also had high scores and were often judged to be significantly better than the other wines in terms of the "fruity and fermentation" character and "general quality" (Table 2). These results correspond to the findings of previous studies, which found that non-Saccharomyces yeasts contributed to mouthfeel and improved the quality of wines (Ciani & Picciotti, 1995;Ciani & Maccarelli, 1998;Minnaar et al, 2015;Ngqumba et al, 2017). The results also support the findings of Albertin et al (2017) on the already mentioned link between non-Saccharomyces yeasts, the duration of the S. cerevisiae lag phase and the wine's fruitiness and complexity.…”

“…The red wine production method was also standardised as described by Minnaar et al (2015). Four T. delbrueckii yeast isolates (strains 654, 206, 301 and M2/1) were inoculated individually.…”

Saccharomyces cerevisiae, Non-Saccharomyces Yeasts and Lactic Acid Bacteria in Sequential Fermentations: Effect on Phenolics and Sensory Attributes of South African Syrah Wines

“…Fermentations were carried out in a temperature-controlled room at ca. 24°C using a standardised winemaking protocol as described by Minnaar et al (2015). Treatments included S. cerevisiae on its own (reference treatment), S. cerevisiae in combination with non-Saccharomyces yeasts, and S. cerevisiae and nonSaccharomyces yeasts in combination with LAB (Table 1).…”

“…Wine phenolic compounds were quantified using a reversedphase high-performance liquid chromatography-photodiode array detection (RP-HPLC-DAD) technique as described by Waterhouse et al (1999) and Minnaar et al (2015). Monomeric anthocyanins, flavan-3-ols, flavonols and phenolic acids were measured at absorbance wavelengths of 520 nm, 280 nm, 360 nm and 316 nm respectively.…”

Effect of Torulaspora delbrueckii Yeast Treatment on Flavanols and Phenolic Acids of Chenin blanc Wines

“…Chenin blanc wines were made according to a standardised small-scale (18 L) white winemaking protocol at the Nietvoorbij Research Cellar (Jolly et al, 2003a;Minnaar et al, 2015) over three vintages (2011,2012,2013). The grapes were crushed, de-stemmed and immediately pressed (with the skins) to 100 KPa in a small-scale pneumatic press.…”