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

Abstract

Water adsorption properties are necessary for determining and analyzing water sorption in dried and roasted cocoa beans during storage. Thus, this study aimed to determine the water adsorption isotherms and thermodynamic properties at temperatures of 25, 30, and 40°C and water activities between 0.10 and 0.85 using dynamic dew point method. Thirteen different models were fitted to experimental data to represent the dependence of the equilibrium moisture content. Additionally, the thermodynamic properties were determined using the best-fit isotherm model. The isotherms of dried and roasted cocoa beans showed typical behavior of products rich in soluble components, according to Brunauer-Emmett-Teller (BET) classification, which was satisfactorily modeled using the Iglesias and Chirife and Kuhn equations, respectively. The thermodynamic properties showed that the net isosteric heat of adsorption and the Gibbs free energy decreased with the equilibrium moisture content, indicating the energy changes and spontaneity during the adsorption process. The integral entropy of adsorption indicated the best conditions for product stability during storage. ARTICLE HISTORY

Moisture sorption isotherms of reduced‐sugar confectionery coatings elaborated with stevia: Mathematical modeling and thermodynamic analysis

“…Maximum values were observed at suggesting that the maximum mobility and vibrational/rotational freedom is achieved before the monolayer is completely covered (Silva et al, 2021) and showing a transition from bound to free water (Quirijns et al, 2005). This behavior was also reported in cocoa beans (Collazos‐Escobar et al, 2020), wheat malt (Silva et al, 2021), Sukkari date powder, dried tomato pulp, and corn stover fractions (Hassan et al, 2020).…”

“…Similar results were obtained by Medeiros et al (2006) for the moisture adsorption isotherms of chocolate powder at 15, 25, and 35°C, where crossover points and the inversion of the temperature effect were observed. Collazos‐Escobar et al (2020), who studied the moisture adsorption isotherms of roasted cocoa beans at 25, 30, and, 40°C, also reported crossover points at 0.81. This antithetical temperature effect observed in foods rich in soluble compounds may be related to phenomena that can affect the product quality.…”

“…Although the sorption heat is usually considered to be approximately independent of temperature, there are many systems where the effect of temperature on is not negligible (Hyla et al, 2019; Sarnavi et al, 2023). In food systems, this effect was observed in formulations containing cocoa (Collazos‐Escobar et al, 2020) and fats (Sun et al, 2023). In the studied samples, the fat present in the CP(i.e., vegetable oil and cocoa butter) could reduce the increase in with , which is usually observed in samples with sugar and proteins.…”

Production of low‐protein cocoa powder with enzyme‐assisted hydrolysis

“…The other main peaks were obtained at 3575–2993, 2916, 2850, and 1736 cm −1 . The strong peaks at the 1500–500 cm −1 fingerprint region were mainly attributed to the carbohydrates (Cerit et al., 2023 ; Collazos‐Escobar et al., 2020 ; Vargas‐Muñoz & Kurozawa, 2020 ). The wide O‐H stretching vibration peaks were detected between 3575 and 2993 cm −1 corresponding to phenols and sugars.…”

“…The other main peaks were obtained at 3575-2993, 2916, 2850, and 1736 cm −1 . The strong peaks at the 1500-500 cm −1 fingerprint region were mainly attributed to the carbohydrates (Cerit et al, 2023;Collazos-Escobar et al, 2020;Vargas-Muñoz & Kurozawa, 2020).…”