Non‐conventional fermentation at laboratory scale of cocoa beans: Using probiotic microorganisms and substitution of mucilage by fruit pulps

Abstract

In a non-conventional lab-scale fermentation of cocoa beans using probiotic microorganisms and substituting the cocoa pulp for fruit pulp, physicochemical, microbiological and quality parameters were investigated. Two hundred grams of beans were fermented in a controlled environmental chamber (temperature ramp rate of 25°C for 48 h; 35°C for 48 h and 45°C for 48 h; and 65% HR). pH, titratable acid, citric, lactic and acetic acids, as well as sugars and ethanol were measured. A cut test was also performed on the cocoa beans fermented 5 and 6 days. As the fermentation time progressed, citric acid concentration decreased until 0.53 g kg À1 , whereas both lactic and acetic acids increased until 0.44 and 16.58 g kg À1 , respectively. Sucrose content decreased from 12.26 g kg À1 (in fresh) to 6.54 g kg À1 on the 6th day. Fructose and glucose contents increased in the cotyledons from day five, reaching a maximum concentration of 1.14 and 1.01 g kg À1 , respectively, on day six. Yeasts were the main microorganisms during the first 24-48 h (8.4 log CFU g À1 ), while bacterial counts reached its highest number (7.8 log CFU g À1 ) on day four. Beans fermented 5 and 6 days resulted in more fermented beans (>81%) and less violet ones (<18.4%) than the control.

Physicochemical changes during controlled laboratory fermentation of cocoa (CCN-51) with the inclusion of fruits and on-farm inoculation

“…Barbosa Santos et al ( 2021) reported that glucose and fructose are the main sugars present in passion fruit and banana, which explains their high levels in this modified fermentation. Other authors observed a different behavior, where the main sugar was sucrose, while glucose and fructose were at low concentrations (Ho et al, 2015;Vizcaino-Almeida et al, 2022). These values may vary depending on the origin of the cocoa, method of determination, degree of maturity of the pulps, sample preparation, type and time of fermentation, and microbial activity (Verce et al, 2021).…”

“…The mixture was thoroughly homogenized and incubated for one hour at ambient temperature (30 °C). Once the mucilage was removed, the cocoa beans were mixed with passion fruit and banana pulps, according to the protocol described by Vizcaino-Almeida et al (2022). The cocoa beans fruit pulps mixture was placed in plastic containers and left for four hours (mixing every 30 minutes) outdoors, allowing the inoculation with the native microorganisms present in the environment.…”

“…In previous studies, a fermentation of CCN-51 cacao beans has been carried out with fruit replacement (passion fruit and banana pulp) and incorporating mixtures of probiotic microorganisms (Vizcaino-Almeida et al, 2022). So far, no results have been reported where the replacement pulps are inoculated with the natural microbiota from the environment and fermented under controlled conditions.…”

Innovation in Cocoa Fermentation: Evidence from Patent Documents and Scientific Articles

“…Ahrert Eskes is the main applicant in patent document WO2009103137A2 [31], which proposes a process to obtain fermented cocoa beans with modified flavors through the addition of aromatic substances such as fruits and pulps during the cocoa bean fermentation process. Positive changes in acidity, sugars, and acids were observed in cocoa beans of the CCN-51 variety, traditionally known as bulk cocoa, fermented with probiotic microorganisms, passion fruit (Passiflora edulis), and banana (Musa paradisiaca) at a laboratory scale for six days [32]. The substitution of cocoa pulp with an artificial cocoa pulp medium during cocoa bean fermentation has also been used to study various fermentation conditions that may improve the quality of cocoa beans [33].…”

“…The top 10 authors presented in Figure 6 are responsible for 30.3% of the publications and are from Belgium (49), Germany (39), Brazil (32), Ghana (14), and France (13). Luc De Vuyst (33) from Belgium and Rosane Schawn (22) from Brazil lead in journal publications on cocoa fermentation.…”