Introduction

Cacao played a pivotal role in the economic, social, religious, and political life of pre-Hispanic Maya. A frothy cacao drink was served to royal newlyweds and the seeds were offered to the bride’s family as a sign of respect from the part of the groom. Cacao seeds were so valuable to Maya (just as jade beans and feathers from the quetzal bird) that they were a strong unit of currency. It follows that cacao was not accessible to society-at-large, being only available to those with power and influence. The scientific name of cacao, Theobroma cacao (i.e., food of the gods) was definitely appropriate and remains a testament to its past (Vail, 2009).

Today, cacao is more commonly referred to as cocoa—a widely traded commodity that continues to be key to the economic and social development of some regions in the world like Côte d’Ivoire, Ghana, or Indonesia where most of the world’s annual crop comes from. However, the importance of cocoa to contemporary society goes well beyond the areas where it is cultivated, mainly because without cocoa, there wouldn’t be chocolate. Except for sugar or milk solids, cocoa contains all the components that make chocolate what it is, although not all in the right proportions. Cocoa butter for example, makes up to 50% of the weight of dried cocoa beans and about 30% in regular dark chocolate (approx. 55% cocoa mass).

Cocoa’s public image—mainly as chocolate—has also significantly and positively evolved over the past few decades as research has demonstrated its association with a range of health benefits. The aim of this chapter is to introduce the reader to the lengthy and chemically complex processes that cocoa undergoes to render the variety of raw materials that enable among others, the chocolate industry. In doing so, the focus will be on those steps that more significantly affect its chemical composition and functionality, particularly when it comes to the putative health benefits of cocoa (see below).

Cacao and Cocoa—From Tree to Factory

Cacao is at the heart of chocolate and it is the reason for its unique sought after flavor and melt-in-mouth characteristics. However, it takes a considerable amount of effort and chemistry, to transform an otherwise inedible cocoa bean into a delicious treat. The cocoa tree (Theobroma cacao, L.) originated from Central and South America (book) where it was cultivated and the seeds of the its fruit consumed by the Preclassic Mayan civilization as early as 600 BC (Hurst, Tarka et al., 2002). Olmec, Mayan, and Aztec peoples enjoyed cocoa as a drink seasoned with chili, vanilla, honey, and annatto (Dircks, 2009). The discovery of America and the subsequent era of colonialism facilitated the migration of the fruit to different parts of the world—in the mid 1500s the Dutch introduced cocoa to Indonesia; in the early 1600s Spain did the same in the Philippines and the West Indies and, in the 1800s, the Spanish, British, and French began cocoa production in West Africa (thesis). However, it wasn’t until the 19th century that cocoa was consumed as a solid food by the general public. Before then, it was a liquid concoction, at times sweetened, and available only to the social elites.

The geographical expansion of cocoa meant that the distinctive attributes of the bean, such as size, flavor, color, chemical composition (e.g., fat, polyphenol, alkaloid content) vary considerably in beans of different origins. Historically, the two main types of cocoa are known as Criollo (T. cacao var. cacao) and Forastero (T. cacao var. sphaerocarpum). The Criollo cocoa variety is recognized for its light color and mild, nutty flavor, as well as its susceptibility to disease and low production yields. Today, this variety is very rare, with only a few plantations still surviving in places like Venezuela or Madagascar (Fowler, 2009). The Forastero variety of cocoa produces beans that are of dark brown color, more strongly flavored, slightly bitter, and possess a higher fat content compared to Criollo beans. The greater part of the world’s cocoa crop has long been considered to be of the Forastero type, more specifically a sub-type known as Amelonado which migrated from Brazil to West Africa in the nineteenth century (Wood, 1991). A third type is known as “Trinitario” which is basically a hybrid of Criollo and Forastero crosses and consequently produces cocoas with special flavors. Last but not least is what is known as “Nacional” which is only grown in Ecuador which is recognized for having an enhanced floral character. Though the type of bean plays an important role in determining flavor, the ultimate flavor of chocolate is a consequence of a complex array of chemical reactions that start from the moment the beans is harvested through the time it is processed into finished chocolate.

The successful cultivation of cocoa requires a special climate that is mostly found within the area bounded by the Tropics of Cancer and Capricorn (10–20° north and south of the Equator). Most trees grow from sea level to an altitude of less than 300 meters. Optimal temperatures lie within the band of 18–30°C (65–86°F) and rainfall of a minimum of 1000–1500 mm must be evenly distributed during the year (Dircks 2009; Fowler 2009). Cocoa is a delicate crop and its trees need to be protected from strong winds as it has a rather weak root system; the soils must be well aerated, and pests and diseases must be carefully controlled. The global production of cocoa has steadily increased in the last three decades, growing at a rate of approx. 2.2% from 1998 to 2010 and the largest cocoa-producing countries are Côte d’Ivoire and Ghana, as together they account for close to 70% of the world crop. Table 2-A describes global cocoa production in the last three decades (http://www.worldcocoafoundation.org/learn-about-cocoa/cocoa-facts-and-figures.html). However, the cultivation and harvesting of cacao beans is seriously threatened mainly by fungal diseases such as black pod, frosty pod, and witches’ broom. Similarly, cocoa is an ‘orphan crop’ in the sense that governments where it is cultivated do not invest in sustainable agricultural programs that enable and incentivize farmers to increase the yields and profitability of their crops. However, the fact that the cocoa genome has been recently elucidated will accelerate the release of robust T. cacao cultivars (Risterucci, Grivet, et al., 2000; Argout, Salse, et al., 2011; Feltus, Saski, et al., 2011; Saski, Feltus, et al., 2011).

Today, it typically takes up to four years for cocoa trees to become productive (an improvement to the common six to seven years of the past) and they can stay productive for 25–30 years (Dircks, 2009; Meursing, 2009). Mature pods, those that measure between 10–15 cm at the center, and are 15–25 cm long, are harvested twice a year as pollination-to-maturity cycle takes about six months. The pod contains some 40 seeds or beans that, after fermentation and drying, make up about 40 g of beans, i.e., an average of 1 g per bean. Yields per hectare have risen over time from around 350 kg to above 500 kg. Today, cocoa trees are cultivated in more than 40 countries around the world, across an estimated area of 3.6 million hectares, producing an annual crop of more than 4.0 million tons of dried beans ready for processing.