# Screening Wild Yeast Isolated from Cocoa Bean Fermentation Using Volatile Compounds Profile  
[PERSON]  
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[PERSON]  
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harvest to harvest, one of the main strategies employed is to standardize the cocoa bean fermentation processes using starter cultures. Spontaneous cocoa bean fermentations are mediated by succession with microorganisms that include yeasts, lactic acid, and acetic acid bacterium, filamentous fungi, and spoilage bacteria. Among these microorganisms, yeasts are essentials because they are involved in the conversion of sugars into ethanol as well as aromatic secondary metabolites that may contribute to the flavor of cocoa [8; 12]. Therefore, there is a consensus that yeasts are mainly responsible for the production of compounds associated with good sensorial characteristics [13]. Selection of microbial strains, in the cocoa industry, for starter culture is based on the properties thereof, such as tolerance to high ethanol, temperature and acid concentration, resistance to low pH, ptenolytic activity, volatiles compounds production with aroma characteristics, microbial stability, and high fermentation activity [14]. For example, [PERSON] et al. [15] isolated 36 yeast ptenolytic strains from spontaneous cocoa beans fermentation that were studied for their response to stress conditions such as high temperature, alcohol, and acid concentration, and low pH. As a result, the authors found that a combination of factors, such as temperature with alcohol or acid, constitute a limiting factor for the growth of ptenolytic yeasts during cocoa bean fermentation. Only strain YS201 was able to develop a response to combined acid and heat shocks. They concluded that the selection of ptenolytic yeasts strains as starter cultures for cocoa fermentation is not an adequate strategy. Similar findings have been reported by [PERSON] et al. [16], who isolated different strains of high-ethanol producers under physical-chemical stress conditions from spontaneous cocoa fermentation. They found that two strains, _Saccharomyces cerevisiae_ YB14, and _Pichia Kudriavzeuii_ YP13, were able to resist parameters such as temperature, pH, ethanol, and organic acids. Thus, these two strains were best adapted to combined metabolite stress and they may be useable in starter cultures in cocoa fermentation. On the other hand, some studies have explored the selection of strains based on volatile compounds production with aroma characteristics. In this context, [PERSON] et al. [13] isolated yeasts associated with spontaneous cocoa fermentation and qualitatively evaluated the aromatic compounds produced by these species. Indeed, the authors identified volatiles compounds produced by _Pichia Kudriavzeuii_, _Saccharomyces cerevisiae_, _Galactomyces geotrichum_, and _Wickerhamomyces anomalies_. These yeasts produced a total of 33 aroma compounds grouped into four families such as esters, alcohols, acids, and others, which could produce a great impact on the sensory qualities of cocoa liquor and chocolate. It is important to mention that yeasts produce volatile compounds (VCs) that can enhance sensory characteristics, but they do not prioritize one in particular, which makes it difficult to design culture starters. [PERSON] et al. [17] selected thermotolerant and high-acetate ester-producing parental _S. cerevisiae_ strains for a generation of new hybrids that combine these two properties. The results showed that these hybrids influence the final chocolate flavor, producing aroma-active flavors and limiting the production of undesired off-flavors. Interestingly, their results indicate that the selection or development of high-acetate ester-producing strains can yield frutier chocolates. Several criteria have been developed to select yeasts for cocoa bean fermentation.