Yeast Diversity during Spontaneous Fermentations and Oenological Characterisation of Indigenous Saccharomyces cerevisiae for Potential as Wine Starter Cultures

Abstract

Diversity of regional yeast can be influenced by geography, grape cultivars and the use of SO2, but at single vineyard scale in China, the impact of these factors on yeast population, particularly Saccharomyces cerevisiae, is not well studied. Here, we characterised yeast species and dynamics during spontaneous fermentations with/without SO2 using eight typical grape cultivars from Yuma vineyard in Ningxia wine region of China. Results show that distribution and abundance of yeast species varied by grape varieties, fermentation stage and SO2 treatment. A number of 290 S. cerevisiae isolates were further classified into 33 genotypes by Interdelta fingerprinting. A prevailing role of grape varieties in shaping the genetic divergence of S. cerevisiae in Yuma vineyard was observed, as compared to the impacts of fermentation stage and SO2 treatment. Pre-selected S. cerevisiae strains were subjected to vinification with Cabernet Sauvignon and Chardonnay. All strains completed fermentations but the physiochemical parameters and volatile profiles of wines were strain-specific. Some indigenous S. cerevisiae yielded more desirable aroma compounds compared to the commercial strains, among which NX16 and NX18 outcompeted others, therefore having potential for use as starters. This study provides comprehensive analysis on yeast diversity at vineyard scale in Ningxia. Information on the vinification using indigenous S. cerevisiae is of great value for improving Ningxia wine regionality.

Effect of multi‐step chaptalisation on physicochemical properties, potentially harmful alcohols, nutritional composition and volatile profiles of kiwi wine

“…The analysis of volatile compounds was performed using gas chromatography–mass spectrometry (GC–MS), in combination with headspace solid‐phase microextraction (HS‐SPME), as previously described (Chen et al ., 2022), with slight modifications. Briefly, 5.0 mL of a sample was placed in a 15 mL glass vial containing 1.0 g NaCl and 10 μL internal standards (4‐methyl‐2‐pentanol, 20 mg/L) and equilibrated at 40 °C with 400 rpm agitation for 30 min.…”

“…The concentrations of the compounds were calculated using calibration curves following Chen et al . (2022), and details of the standards are shown in Table S1.…”

“…Agilent ChemStation was used to qualify and quantify the volatile compounds. The concentrations of the compounds were calculated using calibration curves following Chen et al (2022), and details of the standards are shown in Table S1.…”

Inside Current Winemaking Challenges: Exploiting the Potential of Conventional and Unconventional Yeasts

“…In detail, wines fermented with autochthonous yeasts were characterized by the presence of noticeable esters such as isoamyl acetate (banana scent) and ethyl octanoate (apple, pear, and peach aroma). Consistently, Chen et al [ 74 ] demonstrated how the use of indigenous S. cerevisiae yeasts, as opposed to industrial starters, can lead to an increase in the aromatic composition regarding the production of esters like ethyl hexanoate or ethyl acetate, thus conferring an aromatic distinctive imprint linked to the geographical location [ 74 ].…”

Fungal dynamic during apricot wine spontaneous fermentation and aromatic characteristics of Pichia kudriavzevii for potential as starter

“…Nevertheless, this fermentation method has relied heavily on the raw materials with differently initial microbiota, presenting challenges in ensuring consistency of the final product quality across different batches. Selecting key fermentative species have been regarded as the crux of the transformation from spontaneous fermentation to commercially controlled fermentation, aiming to guarantee the fermentation finish without the interference of polluted species ( Chen et al, 2022 ). Taken together, investigation of microbial diversity with geographical feature in spontaneous fermentation are of high importance for revealing how distinct chemical compositions are formed, and for the selection of expectative starters that can substitute spontaneous fermentation, especially for apricot wines (which has not been proven to date).…”