Aplicação de diferentes metodologias para extração da teobromina e cafeína em amostras de chocolates com distintas porcentagens de cacau por cromatografia líquida

Abstract

Chocolate is a product made from fermented and roasted cocoa beans, it is one of the most consumed foods in the world. There is a wide variety of chocolates, among them we have: milk chocolate, bitter, powder, chocolate, etc. As these products are easily accessible to the consumer, they end up being the main food supplier of theobromine. Likewise, caffeine is found naturally in cocoa beans, and consequently in chocolates. This work aims to determine concentrations of 3,7-dimethylxanthine and 1,3,7-trimethylxanthine alkaloids, commonly known as theobromine and caffeine respectively, by Extraction Method 1 with hydrochloric acid and clarifying reagents and by Extraction Method 2 with sodium hydroxide and dichloromethane in samples of products made from fermented and roasted cocoa beans by Liquid Chromatography with diode array detector. Therefore, samples of chocolate bars with different percentages of cocoa were analyzed, namely: 34%, 55%, 65%, 70% and 85%. Analytical determinations by the chromatographic method showed theobromine concentrations of 57.34; 156.99; 184.21; 255.47; 323.37 mg g-1 respectively the percentages and concentrations of caffeine of 9.58; 38.43; 54.54; 69.55; 89.89 mg g-1 in the proper order. With these results, it can be seen that as the percentage of cocoa increases, the concentrations of theobromine and caffeine increase considerably in the chocolate samples.