Dynamics of Geobacillus stearothermophilus and Bacillus cereus spores inoculated in different time intervals during simulated cocoa beans fermentation

Functional yeast starter cultures for cocoa fermentation

“…Most of the yeasts used as candidate starter culture strains are selected because of their proven prevalence and performance in spontaneous cocoa fermentation processes (Figure 1). Nevertheless, a screening is sometimes performed to ensure the use of the best performing strains regarding pectin degradation, saccharide consumption and ethanol production, tolerance to stress conditions, and/or VOC production (Figueroa-Hernández et al, 2019;Koffi et al, 2018;Pereira et al, 2016Pereira et al, , 2020. Furthermore, besides selecting natural yeast strains with improved qualities, researchers have also developed breeding strategies to generate hybrid yeast strains with increased pectinolytic activity, thermotolerance and/or aromatic potential (Leal et al, 2008;Meersman et al, 2015Meersman et al, , 2016.…”

“…An analysis of the metatranscriptome of spontaneous cocoa fermentation processes has further identified different expression levels of stress response genes in S. cerevisiae compared to H. opuntiae, as well as a shift of gene expression from the early to late stages of cocoa fermentation (Verce et al, 2021). Also, the production of trehalose under varying conditions has been examined to understand the stress response in yeast strains of cocoa origin, since changes in the cell membrane composition and carbohydrate metabolism are part of the yeast response towards stress conditions (Delgado-Ospina et al, 2020;Pereira et al, 2020). These studies support the idea that different yeast species and genera cope with stress conditions in very different ways.…”

“…Finally, an increasing interest in cocoa flavour enhancement by yeasts has resulted in screening studies assessing flavour production by candidate strains (Koné et al, 2016;Meersman et al, 2016;Mota-Gutierrez et al, 2019;Pereira et al, 2017Pereira et al, , 2020. Either the ability to produce isoamyl acetate and ethyl acetate (Meersman et al, 2016) or the production of acetaldehyde and ethyl acetate (Pereira et al, 2017) has been the focus of such investigations.…”

“…However, other microbial groups, such as enterobacteria, filamentous fungi and/or bacilli can also occur, although with a minor contribution to the fermentation process (e.g. pectinolytic activity, citric acid metabolism, pyrazine production) or even undesired activities, given the time frames they are active in during the fermentation and/or drying step (Illeghems et al, 2015; Ouattara et al, 2020; Papalexandratou, Falony, et al, 2011; Pereira et al, 2020; Watson et al, 2013). The contribution of each microbial group is well established (De Vuyst & Leroy, 2020; Santander Muñoz et al, 2020; Watson et al, 2013).…”

Fermentasi Terinduksi Acetobacter aceti dan Saccharomyces cerevisiae untuk Industri Kakao di Kalimantan Timur

“…Perhitungan tersebut masuk dalam batas atas dan bawah aktivitas antioksidan yang diukur dengan regresi non-linier (Gambar 2) pada selang kepercayaan 95%. Faktor-faktor yang mempengaruhi aktivitas antioksidan pada produk kakao fermentasi adalah pemecahan komponen polifenol yang dipengaruhi oleh mikroflora, suhu, dan waktu (Oracz and Nebesny 2016); Pereira et al, 2020). Dalam penelitian ini, faktor yang diduga paling dominan adalah kondisi mikroflora.…”