An Influence of Different Yeast Species on Wine Aroma Composition

Secondary Aroma: Influence of Wine Microorganisms in Their Aroma Profile

“…Among yeasts, S. cerevisiae is capable of synthesizing mainly hexanoic and octanoic acids in high amounts, but also pentanoic, decanoic and 3-methylbutanoic acids. Other non-saccharomyces species such as the genus Hanseniaspora has been described to produce acetic acid (in very variable ranges, from 0.6 up to 3.4 g/L) and species such as Hanseniaspora vineae , H. uvarum , H. guilliermondii or Candida zemplinina displayed higher synthesis rates for isobutyric acid [ 3 , 19 ]. However, it has been stated that this group of yeasts does not present a distinct biosynthesis of fatty acids.…”

“…Even though, the utilization of a mixture of C. stellata and S. cerevisiae could increase the amount of hexanoic and octanoic acids, followed Pichia fermentas . Similarly, the application of sequential inoculations based on S. cerevisiae and non-saccharomyces usually provides wines with lower concentrations of fatty acids [ 3 ]. The use of mixed or sequential fermentations can have benefits to regulate the content of these medium chain fatty acids, since their excessive presence may provide negative aromas with greasy, rancid and cheesy notes [ 3 , 32 ].…”

“…Grapes are known to contain free and sugar-glycosidically-linked terpenes, being the monoterpenes and sesquiterpenes the ones that contribute with aroma and flavor. Among them, the most odoriferous monoterpenes alcohols are linalool, geraniol, nerol, citronellol, 3,6-dimethyl-1,5-octa-dien-1,7-diol, hotrienol and α-terpineol, which provide floral, fruity and citrus aroma to the wine [ 3 , 4 ]. Even though just few aromas have been directly associated to specific varieties, each grape variety possesses an aroma fingerprint.…”

“…Secondary aromas can be divided into pre-fermentative, those arisen due to the mechanical treatment of grapes, and fermentative, those boosted during alcoholic or malolactic fermentation processes [ 1 , 2 ]. The most utilized species for the alcoholic fermentation is Saccharomyces cerevisiae , although there are about 20 yeast genera with the same capacity such as Saccharomycodes , Candida , Issatchenkia , Pichia , Hanseniaspora ( Kloeckera ) or Brettanomyces ( Dekkera ) [ 3 ]. These non-saccharomyces species drive the aroma release by the secretion of proteins, mainly enzymes, and the synthesis of new secondary metabolites.…”

“…Along the fermentation, the main created aromas belong to the volatile fatty acids, higher alcohols, acetate and ethyl ester categories which make evolve the aroma profile of wine [ 3 ]. These molecules are usually present at high sensory thresholds (the oxidation products of linalool possesses a perception threshold of 6000 μg/L) and their combination creates the matrix of wine aroma [ 3 , 13 ]. In fact, by the end of this fermentative stage, the term aroma becomes more complex from a chemical and sensorial point of view and thus, it turns into the term bouquet.…”