CHOCOLATE FACTS: NOT ALL CHOCOLATE IS CREATED EQUAL


Scientists first discovered that cocoa contained flavanols while looking at what gave chocolate its distinctive taste. Research has examined how flavanols work within the cacao plant itself and how they are involved in the flavor profile of chocolate. A general assumption was made that the more cocoa solids in the product, the more flavanols would remain (i.e., dark chocolate or cocoa powder would have more flavanols than milk chocolate). In theory, this makes perfect sense, however, it's much more complex than that. Every step of the manufacture of chocolate, from harvest to the shelf, can affect the levels of flavanols. Therefore, creating a balance between the flavor profile and the flavanol level of chocolate is key.

Flavanols play an important protective role in the cacao plant. It's, therefore, no surprise that compounds created naturally to protect the health of the plant may also help to maintain the health of humans as well (see Chocolate and Flavanols). Research suggests that flavanols work two ways to protect plants: 1) they contribute to the healing of wounds by lignification of cell walls surrounding the wounded areas and 2) through antimicrobial properties. Flavanols can either be present in the plant at the time of the injury or can be produced in response to the injury (1).

Flavanols also influence the flavor profile of chocolate. They are responsible for the astringency in the unprocessed cocoa bean--the more flavanols in the cocoa, the more astringent, or sharp and pungent, the taste will be. The processing of cocoa dramatically affects the levels of flavanols and, in turn, the flavor (2,3,4,5,6,7,8). Furthermore, flavanol levels can vary from plant to plant based on geographic or environmental factors. For example, certain geographic regions naturally produce plants with higher flavanol content while other regions produce higher levels due to environmental factors that place the plants at a higher risk of damage (9).

The process of turning cocoa beans into a consumable chocolate product includes several steps, some of which affect the flavanol level more than others.

* Fermentation - This first step is crucial for the level of flavanols and, subsequently, taste profile. The longer the cocoa beans are fermented, the more flavanols are lost and the less astringent the beans will be. Cocoa-producing regions ferment their beans for different amounts of time, and buyers take this into consideration when selecting which beans they will use in their chocolate products.

* Drying - Good drying practices also relate to the flavor quality of chocolate. Excessive acidity or a smoky flavor can penetrate the beans at this step. Modern technology has allowed for beans to be dried mechanically as opposed to sun-drying, though additional losses of flavanols are possible during both methods. Water activity in beans can sustain the fermentation process and may also result in mold contamination. Therefore, properly dried beans are critical for the end chocolate product to have good flavor.

* Roasting - Roasting temperatures and duration of roasting time significantly affect the flavor and flavanol content of chocolate. Higher temperatures decrease the flavanol content to a greater extent, but flavanols are also lost the longer the beans are roasted.

* Alkalizing ("Dutching") - Alkali is sometimes added to chocolates and cocoa powders for flavor. This process, which increases the pH of the product, has a negative impact on flavanol levels.

* Conching - This step has minimal impact on flavanol level and is mainly for achieving the desired texture and rounding out flavors.

Another generally held belief is that since flavanols attach to proteins, the addition of proteins to a food, such as milk to produce chocolate, would bind the flavanols and decrease their availability for absorption (10). In fact this is not necessarily the case. Although this has not been studied in chocolate, research by scientists in the Netherlands found that the addition of milk to tea, another plant-based food rich in flavanols, does not impair the bioavailability of the flavanols (11).

When chocolate manufacturers begin to select their cocoa beans and start the process of making chocolate products, they are most concerned with flavor. However, as research on the potential health benefits of chocolate flavanols unfolds, it is becoming clear to certain companies that preserving these compounds, while maintaining the flavor that consumers love, is important. Mars, Incorporated, for example, has a proprietary method of processing cocoa beans so that much of the natural levels of flavanols are retained in their chocolate products. The company even labels their products with the CocoaproTM mark, which signifies their promise that the product has undergone this proprietary process.

Additional studies on cocoa and chocolate are ongoing. To receive the most up-to-date information, go to Talk to Us to register for monthly updates.


References
1. Kim H, Keeney P. Polyphenols-Tannins in cocoa beans. 37th PMCA Production Conference, 1983.

2. Kim H, Keeney. (-)-Epicatechin content in fermented and unfermented cocoa beans. J Food Sci 1984;49:1090-2.

3. Jardine NJ. Phytochemicals and phenolics. In Chocolate and cocoa. London: Blackwell Science, p. 119-20, 1999.

4. Haslam E. Practical polyphenolics: from structure to molecular recognition and physiological action. Cambridge: Cambridge University Press, p. 216-9, 1998.

5. Hoskin JC, Dimick PS. Chemistry of flavour development in chocolate. In Industrial chocolate manufacture and use. London: Blackie & Son Limited, p. 108-21, 1988.

6. Robinson T, Ranalli AW, Phillips AW. Changes in cocoa tannins during processing. Agric and Food Chem 1961;9:295-8.

7. Villenueve F, Cros E, Macheix JJ. Effet de la fermentation sur les activités peroxydasiques et polyphénoloxydasiques de la fève de cacao. Café cacao thé 1985;29:113-20.