Physicochemical Changes of Cocoa Beans during Roasting Process

Abstract

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 ( * , * , * ), total phenolic content (TPC), and DPPH radical capacity. Cocoa beans were roasted as a function with a central rotatable design with 2 2 + 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 ( < 0.05) on the response variables except for both TPC and DPPH radical capacity in aqueous extract.

Effect of Fermentation, Drying and Roasting on Biogenic Amines and Other Biocompounds in Colombian Criollo Cocoa Beans and Shells

“…Finally, for hue angle (h • ), a mean value of 55.12 ± 8.26 was determined with a range from 68.77 (sample 2) to 36.49 (sample 6). Other authors reported L* values quite different from those obtained in the present study, while results for parameters of a* and b* were similar [32]. The values obtained for h • were similar to those reported by Sacchetti et al [14].…”

The Kinetics of Total Phenolic Content and Monomeric Flavan-3-ols during the Roasting Process of Criollo Cocoa

“…In Table 1 [46]. The decrease of TPC is associated with the thermal and oxidative degradation of these compounds [35]. It was proven that, at high temperature, low molecular weight phenolic compounds easily volatilize [50].…”

“…In particular, the roasting process leads to the loss or modification of flavanols, which leads to a 14% loss of the total phenolic content (TPC), as well as the epimerization of epicatechin to catechin [25][26][27][28][29][30][31][32].Kinetic modeling can provide a deeper understanding of the changes that occur during thermal processing controlling and food quality optimization [33,34]. Since these roasting techniques were introduced to the chocolate industry, the roasting time and temperature have been studied, applying designs or models that allow for a proper assessment of the process [35]. Various studies have been reported on the effect of roasting on cocoa nibs' coloration, physical/chemical changes [4,5,8,16,23,25,36], flavor changes [37], and the kinetics of polyphenol degradation during drying [12,28,38]; however, studies on the kinetics of the polyphenol and monomeric flavan-3-ol degradation of Criollo cocoa during the roasting process are scarce, so the aim of the present study was to understand this degradation and determine the kinetic parameters.…”

Water dynamics adsorption properties of dried and roasted cocoa beans (theobroma cacao L.)

“…The dried and roasted samples (5 g) were fully dehydrated in an oven at 105°C for 24 h for determining the dry matter and the moisture content. [8] The compositions of dried and cocoa samples (water activity, pH, fat content and acidity; Table 1) were determined according to García-Alamilla et al [8]…”

“…The behavior shown in (Figure 1b) can be explained by chemical transformations during roasting, attributed to Maillard reactions, caramelization of sugars, protein degradation, and synthesis of sulfur compounds. [8] According to Domian et al [10] , the zone (a w > 0.7) is where the water is available as a solvent for low-molecular-weight solutes, wherein the material probably swells and softens, which is where saccharides dissolve; thus, the water is capable of acting as a solvent. In our case, the effect is notorious in the zone (a w > 0.81).…”