Influence of S. cerevisiae and P. kluyveri as starters on chocolate flavour

"Published online in Wiley Online Library: 10 February 2021"BACKGROUND Fermented cocoa beans (Theobroma cacao L.) is a pivotal raw material for chocolate production. A cocktail yeast applied in the cocoa fermentation process can promote the formation of the pleasant metabolites. Saccharomyces, Pichia, and Hanseniaspora have been widely used in fermentation to improve the final product organoleptic profile. Highlighting that fermentation is a critical point for chocolate flavour precursors production. This study aims to evaluate the impact of Pichia kluyveri and Saccharomyces cerevisiae strains as starters cultures on the two cocoa hybrids fermentation FA13 and CEPEC2002. RESULTS During fermentation processes, volatile organic compounds (VOCs) and protein profiles were assessed. Chocolates produced were also assessed regarding the presence of VOCs. Eighty VOCs were identified by gas chromatography coupled to mass spectrometry analysis (HS-SPME GC-MS). Mass spectrometry by the MALDI-TOF technique provided the protein profiles evolution over fermentation and showed they changed with inoculation type (spontaneous vs. inoculated fermentation). Chocolate obtained by FA13 inoculated with S. cerevisiae strain contained higher organics acids amount, being categorised sourer than chocolate produced by spontaneous fermentation of FA13. CEPEC2002 inoculated with S. cerevisiae strain in co-culture with P. kluyveri strain generated less sour and sweeter chocolate than spontaneous fermentation only. CONCLUSION Chocolates from inoculated assays with starter cultures were more accepted by evaluators. Highlighting that P. kluyveri and S. cerevisiae influence the composition of VOCs. Besides, protein profiles also changed throughout fermentation. Further investigation should be conducted to clarify protein degradation dynamics during inoculated fermentations to defining which of both microbial cultures positively affect the chocolate sensory characteristics.The authors thank CNPq/Brazil, FAPEMIG/Brazil and CAPES/Brazil for scholarships, and Fazendas Reunidas Vale do Juliana (Bahia, Brazil). CS thanks Universidad de La Frontera/Chile for partial funding from Project PIA19-0001.