Physicochemical characterization of six yam (Dioscorea spp) species

Yam is a crop with economic and social significance for the Brazilian Northeastern region. The objective of the present work was to analyze the physicochemical characters of six yam species in order to verify variations in chemical composition within the species (inter and intra-species) germplasm. The experimental was performed under a completely randomized design with six treatments and three replicates. Contents of lipids, humidity, ashes, proteins, starch, reducing sugars and the content of total sugars were evaluated. Regarding physical measures, weight of tubers with peel (kg) and weight of tubers without peel (g), tuber length (cm), longitudinal and transversal diameter (cm), longitudinal and transversal thickness (cm) were determined. The results were submitted to analysis of variance (ANOVA), F test and means were compared by the Tukey test (p<0.05) using the statistical software R. High significant statistical difference (p<0.05) was observed for all physicochemical characteristics analyzed. Yam species designated as ‘Jiboia' showed the highest tuber weight (76.96), higher pulp weight (76.26), higher tuber length (74.76) and higher longitudinal diameter (67.76). The species Dioscorea rotundata was also prominent showing higher contents of ashes (1.40), starch (85.20), lipids (1.23) and protein (2.14) and the species D. trifida showed the lowest contents of lipids (0.59), protein (1.07) and reducing sugars (1.06). Results in the present study evidenced inter-specific and intra-specific variations in chemical composition of yam germplams.