Changes in some biochemical qualities during drying of pulp pre-conditioned and fermented cocoa ( Theobroma cacao ) beans (original) (raw)
Related papers
transformed into flavour notes during roasting. The fermentation process triggers an array of chemical reactions within the bean which generate the biochemical precursors of chocolate flavour, aroma and colour [1,4-8]. The process produces alcohol and acids, and generates heat, typically raising the temperature of the fermenting beans to about 45 o C to 50 o C within the first 72 hours. The acids lower the pH and cause acidification or souring of the bean which is a desirable quality in chocolate. The acid and heat generated kills the cocoa bean causing the cell walls within the bean to break down, allowing enzymes to come into contact with their substrates resulting in the beginning of the biochemical changes in the bean [9-11]. During fermentation, bitter and astringent flavours which are due to polyhydroxyphenols such as catechins, flavan-3ols, anthocyanins, and proanthocyanadins are modified in a multi-step process, oxidised and condensed enzymatically into milder tasting substances. Anthocyanins are converted into anthocyanidin by glucosidase enzymes. Anthocyanidin are oxidized by polyphenol oxidase into quinone which combines with amino acids and proteins to form melanin. Polyphenols diffuse out of the bean during the fermentation and are also oxidised by polyphenol oxidases to produce mostly insoluble tannins. The enzymic reactions continue in several ways and yield flavour precursors and some flavour notes [10,12-14]. The great majority of chocolate flavour compounds are formed due to biochemical and enzymatic reactions that occur within the cotyledon [8,10,15-18]. Pulp preconditioning entails changing the properties of the pulp in cocoa beans prior to fermentation and since the pulp is the substrate metabolised during fermentation, changes in the pulp affect the production of acids by lactic acid bacteria, yeasts and acetic acid bacteria [15,19]. The technique reduces the formation of acids throughout the fermentation without enhancing the degradation of acids at the end of fermentation.
IJERT-A Comparative Study of Effects of Drying Methods on Quality of Cocoa Beans
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/a-comparative-study-of-effects-of-drying-methods-on-quality-of-cocoa-beans https://www.ijert.org/research/a-comparative-study-of-effects-of-drying-methods-on-quality-of-cocoa-beans-IJERTV3IS10490.pdf The study was conducted in order to determine and compare the effects of drying methods on quality of fermented cocoa beans. Drying was carried out using two different methods namely oven drying and sun drying methods. Samples were dried at five different oven temperatures of 35 o C, 40 o C, 45 o C, 50 o C and 55 o C while the other samples were sun dried until the moisture content of the samples were reduced to 6-8 %. Each sample was replicated twice. Some quality assessments were carried out for each forced-air drying temperatures and sun drying to compare the quality of sun dried samples with the oven dried ones. The quality assessments were acetic acid level, pH, colour, free fatty acid, acid value and grading. The values obtained were used to determine better method of drying cocoa beans. It was found that the samples sun dried were better than the samples oven dried. Free fatty acid (FFA) and acetic acid levels significantly increased (P < 0.05) with increase in drying temperature while the pH level decreases significantly (P < 0.05) with increase in drying temperature.
Changes in nib acidity, protein and sugar concentration during roasting of pulp pre-conditioned and fermented cocoa (Theobroma cacao) beans were investigated. A 4 × 4 full factorial design with the principal experimental factors as pod storage (0, 3, 7 and 10 d) and roasting time (0, 15, 30 and 45 min) were used. The roasted samples were evaluated for pH, titratable acidity, protein content and sugars concentrations using standard methods. Increasing pod storage caused consistent increases in pH with concomitant decreases in titratable acidity, whereas increasing roasting time caused only marginal and insignificant changes in pH but significantly decreased the titratable acidity. The protein content decreased significantly (P < 0.05) with increasing pod storage and roasting time. Reducing sugars increased marginally with increasing pod storage treatments whiles increasing roasting time significantly (P < 0.05) decreased the reducing sugars of the beans for all pod storage. The...
The sensory profile of unfermented cocoa beans and its changes after moisture treatments
THE 5th INTERNATIONAL CONFERENCE ON AGRICULTURE AND LIFE SCIENCE 2021 (ICALS 2021): “Accelerating Transformation in Industrial Agriculture Through Sciences Implementation”
Unfermented cocoa bean has an astringent and bitter taste in addition to a weak cocoa aroma. It lacks of precursors of aroma due to incomplete enzymatic processes within the cotyledon. The enzymes responsible for development of aroma precursors could be reactivated by incubating it in moist condition. Unfermented cocoa beans were dried, cleaned from shelled, ground and pressed to produce powder. It was mixed with distilled water at ratio 1 g :1.5 ml and was incubated for 4, 8, or 16 hours. Fermented cocoa was prepared in the same manner without moisture treatment, as a control. Parameters observed were total polyphenols, reducing sugars, and sensory properties. Principal Component Analysis (PCA) and Pearson's Correlational analysis were performed to assess the relationship between parameters. The sensory evaluation shows that unfermented cocoa is characterized with green, earthy, astringent, and bitter notes. Fermented cocoa has a welldefined chocolate, caramel and nutty notes. Moisture treatment of unfermented cocoa for 4 hours and 8 hours treatments enhanced the sweet and caramel note. There was a strong positive correlation between polyphenol content and bitter (r = 0.95, p < 0.05) and astringent (r = 0.93, p<0.05) notes, as well as between reducing sugar and sweet, chocolate, caramel and nut notes. These correlations indicates that polyphenols and reducing sugar content could predict the sensory quality of cocoa. This study demonstrates the potential of moisture treatment to improve sensory quality of unfermented cocoa.
Changes in Chemical Properties of Dreid Cocoa (Theobroma cacao) Beans during Fermentation
Changes in acidification and sugars of cocoa pulp during fermentation of pulp pre-conditioned cocoa (Theobroma cacao) beans were investigated using a 3 × 3 full factorial experimental design with tree level treatment (control (TI), inoculum added in begin fermentation (IA), inoculum added in step (IB) and fermentation time as principal factors. pH, non-volatile (titratable) acidity, reducing sugars, and fermentation indexes of cocoa beans were studied using standard analytical methods. pH of the cocoa nibs increased with inoculum added and fermentation with consequential decrease in non-volatile acidity. Contrary, inoculum added and fermentation decreased the reducing sugars in cocoa nib. The most abundant fermentation indexes in unfermented cocoa bean with values of (TI) 0.31 – 0.88, (IA) 0.32 – 0.99, (IB) 0.33 – 1.03).
International Food Research Journal
Studies were conducted to establish changes in nib acidification and biochemical composition (sugars concentration, proteins and free fatty acids) during fermentation of pulp pre-conditioned cocoa beans using a 4 x 3 full factorial experimental design with pod storage (0, 3, 7 and 10 days) and fermentation time (0, 3 and 6 days) as the principal factors. Non-volatile (titratable) acidity, pH, sugars (reducing, non-reducing and total sugars), proteins and free fatty acids of the beans were studied using standard analytical methods. Pod storage caused consistent increases in pH of the nibs at all fermentation times with consequential decrease in non-volatile (titratable) acidity. Bean fermentation from pods stored between 3–7 days resulted in cocoa nibs with pH between 5.10–5.36 with only minimal changes in FFA. However, fermentation significantly (p < 0.05) decreased the non-reducing sugars, total sugars and protein content of the beans whilst reducing sugars increased. Similarly,...
Preliminary empirical studies have suggested a likely relationship between cocoa pulp flavour attributes and the expression of fruity and/or floral flavours in "fine" or "flavour" cocoa genotypes. In the current study, the aromatic pulp of two tropical fruit species (Theobroma grandiflorum and Anona muricata) was added to Amelonado cocoa beans during the fermentation process to further assess the possible effect of the cocoa bean flavour environment on the flavour attributes of cocoa nibs and of chocolates. The fruit pulps were added in equal quantities to wet Amelonado cocoa beans in micro-fermentation bags placed in the middle of an Amelonado fermentation mass one or two days after the start of the fermentation process. Organoleptic analysis of the fermented and dried cocoa nibs, and of cocoa liquors and chocolates made with beans from the mixed micro-fermentations revealed the presence of flavour attributes from T. grandiflorum and A. muricata. This suggests t...
Proceedings of the International Symposium on Cocoa Research (ISCR), Lima, Peru, 13-17 November 2017, 2017
The objective of this study was to compare the drying behavior of fermented cocoa (Theobroma cacao L.) beans dried in a traditional cocoa house replica and greenhouse-type dryer with that of beans dried in a mechanical cabinet oven at 40°C (drying for 8h with a rest period of 16h). Weight measurements were taken at the start of drying and at regular intervals during the drying process, and drying continued until there was no change in bean weight. Moisture content, water activity, pH and color attributes were measured at the start and at the end of drying. Sensory evaluation of the cocoa liquor was done on the dried samples. Initial moisture content of beans averaged 1.04 g H2O/g DM (50.9% wb). Final (equilibrium) moisture values attained after 11.4 days of drying in the cocoa house and the greenhouse and after 9.3 days of drying in the oven averaged 0.60, 0.70 and 0.50 g H2O/g DM (2.3-4.6 % wb), respectively. During the first 3 days of drying, the decline in moisture content was si...
2016
Fermented cocoa bean is the main ingredient of chocolate products because through fermentation the required flavour and aromas can be obtained. The proper fermentation methods applied is a must in order to produced chocolate with high quality because the specific aromas compound cannot be obtained from incomplete fermentation of the beans. Fermentation is carried out by microorganisms that dominating the fermentation inoculum. The microorganism that have been found to be important in order to reached cocoa fermentation succession are yeast, lactic acid bacteria and acetic acid bacteria as their activities will affect the physical and chemical properties of the fermented cocoa bean. Chemical that have been synthesized by those microorganisms will affect the taste and colour of the cocoa bean. By regulating the fermentation culture and pod storage practice, high fermented cocoa bean quality can be produced. By using starter cultures from specific species of yeasts, lactic acid bacteri...
Physicochemical Changes of Cocoa Beans during Roasting Process
Journal of Food Quality, 2017
During cocoa beans roasting, there are physicochemical changes that develop the chocolate quality attributes. Roasting systems have a particular influence on the development of these characteristics, and the effects of operation variables for each system must be evaluated. The objective of this study was to evaluate the effect of roasting time and temperature in a rotatory system on cocoa beans physicochemical parameters of quality as moisture, water activity, pH, total acidity, color (L⁎,a⁎,b⁎), total phenolic content (TPC), and DPPH radical capacity. Cocoa beans were roasted as a function with a central rotatable design with 22 + 5 central points and 4 axial points (-1.414, -1, 0, +1, and +1,414) and a response surface methodology was applied. Temperature and time levels were 110–170°C and 5–65 minutes, respectively. The effect of the variables was nonlinear and modeled with a second-order response polynomial. Roasting time and temperature presented a significative effect (p<0....