Effect of the solar drying process on the sensory and chemical quality of cocoa (Theobroma cacao L.) cultivated in Antioquia, Colombia

Abstract

The quality of Theobroma cacao L. is influenced by different variables both in the crop and in the processes of postharvest, the latter it includes the fermentation and the drying, fundamental for the formation of aroma and flavor precursors, determinants in the characteristics of quality and differentiation of cocoa in the chocolate industry. The objective of the present research was to evaluate the effect of the solar drying process using a plastic roof solar dryer on the sensory and chemical quality of a mixture of cocoa cultivated in a region of Antioquia, Colombia. The content of total polyphenols, anthocyanins, sugars, mannitol, pH, total acidity, humidity, ethereal extract, ash, crude fiber and odor and flavor descriptors were analyzed. For analyzing the data, we used the methodology of longitudinal data analysis and repeated measurements, a Principal Component Analysis (PCA), and a principal factor analysis. The analyzed sensory characteristics are statistically different over time (p < 0.05). There was a decrease in the content of anthocyanins, total polyphenols and sucrose, and an increase in glucose and fructose during fermentation and drying. The analysis of factors allowed to define a series of groupings as indexes of quality according to the chemical and sensory properties analyzed in the drying process. Overall, the mixture of cocoa clones evaluated in the solar drying process presented indicators of sensory and chemical quality associated with descriptions of odor (spicy, dairy, nut, fruity, sweet cane), flavor (floral and spicy), ethereal extract, and pH that indicate a good benefit of cocoa and show the potential that Colombia has as a producer of fine aroma cocoa in high demand in premium markets.

Keywords: Chemical characterization, Multivariate Analysis; Fermentation; Sensory analysis; Solar drying; Theobroma cacao L.