Biometry and verification of papermaking potential of secondary xylem fibers of two Theobroma species

Theobroma glandiflorum and T. cacao, known as cupuacu and cacao, respectively, are species widely used for food purposes. However, when plantations are renewed, these plants are discarded, making studies on the reuse of this material necessary. Thus, the objective of this study was to perform biometry of cellular elements and to investigate the papermaking potential of the fibers of these two species. We used the cellular element maceration technique to measure fiber and vessel element dimensions and calculated the fiber slenderness ratio, wall fraction, coefficient of flexibility and the Runkel index. According to the classification literature, the fibers of these species were of medium size, and there was a significant difference in wall thickness, with cupuacu fibers being thicker. The values of the fiber slenderness ratio and the coefficient of flexibility were higher in cocoa, while those of wall fraction and the Runkel index were higher in cupuacu. To conclude, the fibers of both species have papermaking potential. However, the paper manufactured with these fibers should be tested to confirm the results of this study.