According to Pharma Exchange, in Pharmacognosy and Health Benefits of Cocoa seeds(Chocolate), at http://pharmaxchange.info/press/2013/07/pharmacognosy-and-health-benefits-of-cocoa-seeds-chocolate/, the cocoa contains alkaloids, and the most important ingredients are theobromine, caffeine, and trigonelline. Chocolates containing cocoa are a rich source of procyanidins which are useful antioxidants.
...The presence of procyanidins in cocoa has been attributed to have antioxidant activity (scavenge free radicals) and also to inhibit lipid peroxidation
thus in turn lowering cholesterol levels.

To read more about cocoa benefits, click the above link.
Bruama's doesn't use any other ingredient than cocoa, sugar (cane, or coconut palm sugar, or stevia, or xylitol sugar) and milk when making its chocolates.

At Food-Info (http://www.food-info.net/uk/qa/qa-fi63.htm), you can learn about emulsifiers and why are they used in the chocolate industry. Here a portion of the information about chocolate: "
All chocolate products contain 0.5% of lecithin (E322) or ammonium phosphatide (E 442). These emulsifiers are added to provide the right consistency of the chocolate, so it can be moulded into plates of chocolate, chocolate bars etc.
If the chocolate has been stored at too high temperatures, its surface may appear dull or white. This is called ‘bloom' which makes the product less attractive to the customer. Sorbitan tristearate (E 492) can delay the development of bloom.
"
For more information on Yerba Mate tea nutritional values, visit the page ahead: http://www.matefactor.ca/yerba-mate-learning-centre-all-about-yerba-mate/yerba-mate-nutrition-en.html
: "...More Antioxidants than Green Tea - Antioxidants in Yerba Mate

Studies show Yerba Mate to be higher in antioxidants than Green Tea. Partially responsible for this is the high levels of polyphenols found in Yerba Mate. Polyphenols are indicated to perform similarly to the 293 natural antioxidant enzymes in the body, and are believed to support these natural health promoting systems.
Largely responsible for the high antioxidant value of Yerba Mate are the very high levels of caffeoyl derivatives found in Mate compared to other plants. These include caffeic acid, chlorogenic acid, 3, 4-dicaffeoylquinic acid, 3, 5-dicaffeoylquinic acid, and 4, 5-dicaffeoylquinic acid.
...
The Healthy Energizer

The energizing effects of Yerba Mate are longer lasting than traditional caffeine beverages, and are found by most to be free from side effects such as, the jitters, mood swings, addiction, and post stimulation fatigue. The bottom line is, Yerba Mate gives you energy that really feels good.

Yerba Mate has 3 xanthine alkaloids, working together with a rich host of nutritional components, creating the unique healthy energizing effect. The xanthines are caffeine, theobromine and Theophylline. Mate is low in caffeine, and theophylline, yet high in theobromine, which has less effect on your nervous system than caffeine. A hypothesis exists that Yerba Mate contains its own unique xanthine alkaloid that hasn't been clinically identified yet.

... the overwhelming majority have reported that Yerba Mate does not give them the health problems they experience from coffee. Many who have had problems with caffeine and desire to get off of it, find Yerba Mate to be the answer they were looking for.'''