Effect of drought stress on the morphological and physicochemical properties of starches from Trimezia juncifolia

In this study corms from Trimezia juncifolia were collected in the wet (WSS) and dry (DSS) seasons and used for extraction of starch. Results evidenced that drought stress interfered with the yield, morphological and physicochemical properties of the starches. In addition, it was observed a higher content of amylose for DSS (44%) when compared with WSS (41%). Drought stress did not interfere with the degree of polymerization (DP) of amylopectin, whereas decreased the amylose DP for DSS. Also, starch granules changed from A-type polymorph in the DSS to a C-C-type in WSS. Drought stress reduced the starch crystallinity from 27% in WSS to 25.9% in DSS. In addition, the endothermic transition temperatures and enthalpy change of transition were also affected by drought stress. Finally, results clearly demonstrate that changes in the morphological and physicochemical properties of the starch granules figure as adaptive strategies of T. junciolia to drought stress.