Formulation and Characterization of a Theobroma cacao—Based Bar with the Addition of Foeniculum vulgare Essential Oil

Cacao (Theobroma cacao) is considered a functional food due to its composition, which is rich in bioactive compounds such as flavonoids, theobromine, dietary fiber, and essential minerals. Several studies have shown that flavonoids have antioxidant and anti-inflammatory properties, helping to reduce oxidative stress and protecting against cardiovascular diseases. In addition, their ability to stimulate nitric oxide production improves blood circulation and lowers blood pressure. These benefits, coupled with its ability to improve mood and cognitive function, position cocoa as a key ingredient in the development of functional foods aimed at improving quality of life and preventing chronic diseases. This research aims to create a product that incorporates cocoa and essential oils extracted from aromatic plants native to the department of Cauca. This represents a significant step toward the sustainable use of these ingredients in the region, promoting consumer welfare and health while strengthening sustainable practices, fostering innovation, and boosting economic and social development in the department. The research is developed in five phases: determination of the study area, characterization of the cocoa production chain in the department of Cauca, selection of essential oils, application of an experimental mixture design and physicochemical and microbiological analyses of the final product. From the experimental design of the mixture, it was determined that the most appropriate formulation of the bar is 60% dark chocolate (70% cocoa), 29% sweet chocolate, 10% pure strawberry and 1% fennel essential oil (Foeniculum vulgare), reaching an average sensory acceptability of 3.23 on a five-point hedonic scale. The qualitative properties (organoleptic, chemical and microbial) of the selected formulations are acceptable for human consumption and provide a high energy content of 506.25 kcal/100 g for chocolate bars filled with strawberry puree and fennel essential oil.