Formation of Aromatic and Flavor Compounds in Wine: A Perspective of Positive and Negative Contributions of Non-SaccharomycesYeasts

Abstract

Wine is a complex matrix that involves compounds of different chemical nature, with volatile compounds being primarily responsible for the aromatic quality of the wine. The formation of these volatile compounds is mainly due to yeasts' metabolism during alcoholic fermentation. Several studies in the microbiology field have reported that Saccharomyces cerevisiae is responsible for alcoholic fermentation, influencing the sensory quality of the wine and affecting the metabolic activity of other genera and species of yeasts, called non-Saccharomyces, which would positively affect sensory quality. Non-Saccharomyces yeasts, considered until recently as undesirable or spoilage yeasts, can improve the chemical composition and aroma profile of the wine. The activity of these yeasts is considered essential for the final wine aroma profile. Thus, the metabolism of these microorganisms could be a decisive factor that strongly influences the aroma of the wine, impacting on its quality. However, there are few studies that explain the impact of non-Saccharomyces yeasts on the final wine aroma profile. This chapter summarizes relevant aspects and pathways involved in the synthesis of aromatic compounds by non-Saccharomyces yeasts as well as studies at the genetic and transcriptional level associated with their formation.

Influence of Non-Saccharomyces on Wine Chemistry: A Focus on Aroma-Related Compounds

“…Flavouring benzenoid compounds present in non-barrel-aged wines are mainly derived from grape. Main are vanillin (vanilla note), ethyl-vanillate (flowery), methyl-vanillate (dry herbs), -phenylethanol (rose note) [28], zingerone (sweet, fruity, cooked pears notes) [29], and methyl salicylate (floral note, slightly balsamic, tending to cinnamonchestnut honey) [19,22,[30][31][32].…”

High Potential of Pichia kluyveri and Other Pichia Species in Wine Technology

“…P. fermentans has been described as low acetic acid producer in different combinations and conditions; the species does not exceed the acid levels reached in fermentation with only S. cerevisiae . In a two-day fermentation, it allowed a considerable increase of aromatic compounds such as acetaldehyde (70%) and glycerol (by around 1000 times) [ 54 , 55 ]. In a recent study using a P. fermentans strain as inoculum for pilot scale fermentation in 1000 L, a slight decrease in ethanol yield was observed compared to S. cerevisiae control (12.80% v / v compared to 13.00% v / v ), and an increase in volatile acidity (20%) and volatile compounds such as acetaldehyde (10%) and 2 -methyl- 1 -propanol (53%) [ 56 ].…”

Improvement of Torulaspora delbrueckii Genome Annotation: Towards the Exploitation of Genomic Features of a Biotechnologically Relevant Yeast

“…Non- Saccharomyces species have long been associated with wine fermentation spoilage, mainly due to their negative sensorial traits and low fermentation abilities [ 1 , 2 , 3 , 4 ]. However, this paradigm has changed recently since positive effects, especially at the level of sensory attributes, have been reported for several non- Saccharomyces species [ 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. Torulaspora delbrueckii , being genetically close to S. cerevisiae , has received significant attention for the benefits it brings to the wine and baking industries.…”