The Important Contribution of Non-Saccharomyces Yeasts to the Aroma Complexity of Wine: A Review

Abstract

Non-Saccharomyces yeast plays an important role in the initial stages of a wild ferment, as they are found in higher abundance in the vineyard than Saccharomyces cerevisiae. As such, there has been a focus in recent years to isolate these yeast species and characterize their effect on wine fermentation and subsequent aroma. This effect on wine aroma is often species and strain dependent, as the enzymatic profile of each yeast will determine which aroma compounds are formed as secondary metabolites. Semi-fermentative yeast, such as Hanseniaspora spp., Candida spp. and Metschnikowia pulcherrima, are commonly in high abundance in fresh grape must and have diverse enzymatic profiles, however they show a weak tolerance to ethanol, limiting their impact to the initial stages of fermentation. Fully fermentative non-Saccharomyces yeast, characterized by high ethanol tolerance, are often found at low abundance in fresh grape must, similar to Saccharomyces cerevisiae. Their ability to influence the aroma profile of wine remains high, however, due to their presence into the final stages of fermentation. Some fermentative yeasts also have unique oenological properties, such as Lanchancea thermotolerans and Schizosaccharomyces pombe, highlighting the potential of these yeast as inoculants for specific wine styles.

Hanseniaspora vineae and the Concept of Friendly Yeasts to Increase Autochthonous Wine Flavor Diversity

“…These aroma compounds can be defined as “toxic” intercellular communication mechanisms, in contrast to the reduced production of these flavors by a friendly yeast strain. During the last decade or more, many non- Saccharomyces starters in mixed culture fermentation with a strain of Saccharomyces have been studied, usually inoculated in sequential mode, so as to enhance the opportunity of the non- Saccharomyces to influence the winemaking process compared with co-inoculations where its impact can be limited by exclusion or competition with Saccharomyces ( Padilla et al, 2016 ; Aranda, 2019 ; Borren and Tian, 2021 ). In summary, the competitive advantage of Saccharomyces over the majority of non- Saccharomyces yeasts can reside in various stress mechanisms, including nitrogen depletion, sugar transporter adaptations to high osmotic pressure of grape juice (high sugar content) and to a more active proton-pump ATPase adapted to low pH and high ethanol ( Ganucci et al, 2018 ; Palmgren and Morsomme, 2019 ).…”

“…The challenge was to return to traditional winemaking technologies but guided by a greater wealth of knowledge compared with earlier times ( Carrau, 2006 ; van Wyk et al, 2020 ). It is now well established that increased yeast diversity can contribute to the diversity of the volatile chemical composition of wine ( Romani et al, 2020 ), which might increase the sensory diversity of wine flavor, a still controversial concept of sensory complexity ( Varela et al, 2009 ; Smith, 2012 ; Köster and Mojet, 2016 ; Borren and Tian, 2021 ). Moreover, increased diversity can also results in process stability and productivity in microbial communities ( Lehman and Tilman, 2000 ; Briones and Raskin, 2003 ).…”

Effects of co-inoculation and sequential inoculation of Wickerhamomyces anomalus and Saccharomyces cerevisiae on the physicochemical properties and aromatic characteristics of longan (Dimocarpus longan Lour.) wine

“…An OAV larger than 1 indicates that the compounds make a great contribution to the aroma of wines. On the contrary, an OAV lower than one implies that the compounds contribute little to the aroma (Borren and Tian, 2020). The OAVs of 14 main aromatic compounds in longan wine are displayed in Table 7, and the OAVs of 10 compounds were greater than 1, while those of four compounds were less than 1.…”

Traditional Fermented Beverages of Mexico: A Biocultural Unseen Foodscape

“…The main microorganism referred to in the studies is S. cerevisiae, which is a common species in fermented products around the world and it is frequently found in alcoholic beverages. Surprisingly, it is possible to see in the network that the non-Saccharomyces species form a node; this is a trend around several industrialized beverages, such as beer [70], wine [143], and recently in cocoa fermentation [144], which looks for flavors and aromas in the final products. Research has been directed to characterize bacteria in the traditional fermented beverages, mainly because most of these beverages pass through a lactic fermentation stage, but perhaps the most common purpose is the isolation and evaluation of these bacteria to improve human health [145].…”