Physicochemical Phenomena in the Roasting of Cocoa (Theobroma cacao L.)

Phenolic content and oxidative stability of chocolates produced with roasted and unroasted cocoa beans

The aim of this study was to produce chocolate using roasted (RB) and unroasted cocoa beans (URB). The effect of roasting on the total phenolic content (TPC), antioxidant activity [2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity, ferric reducing antioxidant power (FRAP), and cupric ion reducing antioxidant capacity (CUPRAC) values], phenolic compounds, caffeine, oxidative stability [free fatty acid, peroxide, conjugated dienes, conjugated trienes, and thiobarbituric acid reactive substances (TBARS)], Fourier transform infrared (FTIR), and differential scanning colorimetry (DSC) analysis of both cocoa beans and chocolate samples were analyzed. According to the results, the TPC of URB (24.96 mg gallic acid equivalent (GAE)/g sample) was higher than roasted beans (21.32 mg GAE/g sample). Similar results were also seen in the TPC of chocolate samples. Although roasting did not affect the DPPH scavenging activity and caffeine content of cocoa beans, it decreased FRAP and CUPRAC values. (-)-Epicatechin and chlorogenic acid values were higher in unroasted bean and chocolate samples, but the amount of gallic acid increased with the roasting process. Free fatty acid, peroxide, conjugated dienes, conjugated trienes, and TBARS results of unroasted samples were lower than roasted ones, indicating better oxidative stability. The melting temperatures of cocoa beans changed with roasting while it was similar between chocolate samples. Composition of the beans and the chocolate samples were qualitatively determined with FTIR.

Can Chocolate Be Classified as an Ultra-Processed Food? A Short Review on Processing and Health Aspects to Help Answer This Question

Chocolate is a confectionery product whose consumption has increased, particularly dark chocolate. Chocolate is produced with varying amounts of cocoa liquor (CL), cocoa butter (CB) and cocoa powder (CP). The main chocolate types are dark, milk and white. Processing steps for chocolate production are described, and nutritional compositions examined for benefits and risks to health. Chocolate processing comprises steps at farm level, initial industrial processing for production of CL, CB and CP (common for all chocolate types) and mixing with other ingredients (like milk and sugar differing according to chocolate type) for industrial chocolate processing. All chocolate types present similar processing levels, and none involve chemical processing. Nutritional profiles of chocolate products differ according to composition, e.g., dark chocolate contains more CL, and so a higher antioxidant capacity. Chocolate is an energy-dense food rich in bioactive compounds (polyphenols, alkaloids, amino acids). Studies have demonstrated benefits of moderate consumption in reducing cardiovascular risk and oxidative and inflammatory burden, improving cognitive functions, maintaining diversity in gut microbiota, among others. In our view, chocolate should not be classified as an ultra-processed food because of simple processing steps, limited ingredients, and being an important part of a healthy diet when consumed in moderation.

Forastero and Criollo cocoa beans, differences on the profile of volatile and non-volatile compounds in the process from fermentation to liquor

Cocoa bean fermentation is an important process because during this process, aroma compounds are produced, the astringency decreases, and the embryo dies. The fermentation processes of the Criollo and Forastero types have been studied separately without comparing them at the same time and in the same place. The aim of this work was to determine differences in the profile of volatile and nonvolatile compounds of Criollo and Forastero cocoa from the fermentation process to the final stage of obtaining the liquor. The experiments were carried out at the same time in the Maya region. Volatile compounds were determined by HS-SPME GC-MS (headspace solid phase-microextraction with gas chromatography-mass spectrometry). Sugars, organic acids, and alkaloids were determined by ultrahigh-performance liquid chromatography (UHPLC-PDA/UV). Criollo cocoa liquor was defined by the volatile and nonvolatile compounds such as acetic acid, phenylethyl alcohol, benzaldehyde, 2-phenylethyl acetate, acetophenone and 3-methylbutanal., which are associated with sour, honey, almond, flowery and chocolate aroma. Forastero cocoa liquor was represented with a significant difference by acetic acid, isobutyl acetate, 2,3-diethyl-5-methylpyrazine and ethyl octanoate and these could provide aroma descriptors such as sour, fruity and nutty. This study characterized for the first time the dynamics of volatile compounds during the fermentation, drying, and roasting stages and in the final cocoa liquor of Criollo and Forastero from cocoa beans of the same origin.

The impact of roasting on cocoa quality parameters

Roasting is an essential process in cocoa industry involving high temperatures that causes several physicochemical and microstructural changes in cocoa beans that ensure their quality and further processability. The versatility in roasting temperatures (100 - 150 °C) has attracted the attention of researchers toward the exploration of the effects of different roasting conditions on the color, proximal composition, cocoa butter quality, concentration of thermolabile compounds, formation of odor-active volatile organic compounds, generation of melanoidins, production of thermal processes contaminants in cocoa nibs, among others. Some researchers have drowned in exploring new roasting parameters (e.g., the concentration of water steam in the roasting chamber), whilst others have adapted novel heat-transfer techniques to cocoa nibs (e.g., fluidized bed roasting and microwaves). A detailed investigation of the physicochemical phenomena occurring under different cocoa roasting scenarios is lacking. Therefore, this review provides a comprehensive analysis of the state of art of cocoa roasting, identifies weak and mistaken points, presents research gaps, and gives recommendations to be considered for future cocoa studies.