From Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action.

Despite the health benefits associated with the ingestion of the bioactive compounds in cocoa, the high concentrations of polyphenols and methylxanthines in the raw cocoa beans negatively influence the taste, confer the astringency and bitterness, and affect the stability and digestibility of the cocoa products. It is, therefore, necessary to process cocoa beans to develop the characteristic color, taste, and flavor, and reduce the astringency and bitterness, which are desirable in cocoa products. Processing, however, affects the composition and quantities of the bioactive compounds, resulting in the modification of the health-promoting properties of cocoa beans and chocolate. In this advanced review, we sought to better understand the effect of cocoa's transformational process into chocolate on polyphenols and methylxanthine and the mechanism of action of the original flavanols and methylxanthines. More data on the cocoa processing effect on cocoa bioactives are still needed for better understanding the effect of each processing step on the final polyphenolic and methylxanthine composition of chocolate and other cocoa products. Regarding the mechanisms of action, theobromine acts through the modulation of the fatty acid metabolism, mitochondrial function, and energy metabolism pathways, while flavanols mainly act though the protein kinases and antioxidant pathways. Both flavanols and theobromine seem to be involved in the nitric oxide and neurotrophin regulation.

Investigating the effect of different types of cocoa powder and stabilizers on suspension stability of cinnamon-cocoa drink.

Sedimentation of particles in cocoa drink is a technological challenge for the food industry. This study investigates the effect of different stabilizers (alginate, xanthan gum or carrageenan) on the suspension stability of cinnamon-cocoa drink made from 2 types of cocoa powder (natural or alkalized). Rheological and microstructural properties determination was used to examine the stabilization effect mechanism. The cocoa powder characteristic was investigated to study the correlation between cocoa powder properties and suspension stability. The results showed that xanthan gum is the most effective stabilizer to prevent particle sedimentation of the cinnamon-cocoa drink. Xanthan gum formed a network entrapping the particles. It increased the viscosity from 2.47 to 70.44 mPa s at a shear rate of 10/s. The drink formulated with alkalized cocoa powder has a better stability than that formulated with natural cocoa powder. However, at the concentration of 0.1% (w/v), xanthan gum could prevent sedimentation regardless the type of cocoa powder. The addition of xanthan gum up to 0.1% (w/v) had no significant effect on pH and antioxidant properties of the cinnamon-chocolate drink with a minor change in the lightness (L*) parameter. As such, the value of L*, pH, phenolic content and antioxidant activity of the cinnamon-cocoa drinks remained stable at around 22.5 ± 0.9, 7.2 ± 0.1, 0.31 ± 0.5 mg epicatechin equivalent /ml and 0.44 ± 0.3 mg tannic acid equivalent /ml, respectively. This study can be useful for the food industry to define a novel strategy to produce "ready-to-drink" cocoa-based beverage with prolonged suspension stability.