The food of the gods - the chemistry from cacao bean to chocolate bar.

Chocolate, made from Theobroma cacao seeds, is a food high in economic and hedonic value. Loved by virtually everyone and accruing >USD120,000m revenue annually, it is also the center of much scientific research. The unique flavors of chocolate can be traced to multiple sources, including tree genetics, post-harvest treatments, (e.g., fermentation and drying) and final processing (e.g., roasting, grinding, conching). Recently, the rise of the fine-flavor cocoa industry has re-started investigations into flavors tied to specific country-of-origin and tree genetics. Cocoa and chocolate are also high in polyphenols and secondary metabolites of interest from a nutritional and health perspective. Chocolate consumption has been associated with cardiovascular health benefits in epidemiological studies, and increasing evidence that such benefits cannot be explained by direct absorption of individual compounds, but rather point at indirect modes of action, including a potential role of the gut microbiome. The molecular biology and biochemistry of cacao metabolites and their genetic and environmental regulation is another important focus of cacao, cocoa, and chocolate chemistry research. The future of the T. cacao tree depends on cultivars that increase the livelihood of the mostly small-scale cacao farmers through increased yield, resistance against biotic and abiotic factors, and also special flavors and higher safety, including low Cadmium uptake. Along the process chain, chocolate product safety, made in small-scale and craft operations, also requires attention. With the trend to lower roasting temperatures and even raw, unroasted chocolates, the risk of food-born pathogen survival throughout the process increases. Understanding individual contributions of these factors, and their combined effects requires robust experimental designs, sophisticated analytical methods, and interdisciplinary collaborations, to ensure the safety, quality and deliciousness of chocolate. This talk provides an overview of various aspects of chocolate chemistry, from cacao tree and seed all the way to the final chocolate bar.