Morphological Characteristics of Starch Granules from Yam Tuber Parts of "Florido" and "Bètè-Bètè" Cultivars (Dioscorea alata) During the Post-harvest Storage

Abstract

It is paramount important to know that starches are extracted from tuber parts of two yam cultivars (Dioscorea alata) during the post-harvest storage for up to 6 months. The granules related to these starches were investigated for morphological properties during post-harvest storage. The results revealed that the shapes of the starch granules did not vary from one part to another, even if the cultivar is for the same storage time and during the post-harvest storage. Indeed, the tuber parts of "Bètè-bètè" cultivar are constituted of granules with round, oval and oblong shape. Besides, the shape of starch granules of "Florido" cultivar varied from round to ovotriangular. In general, the distribution of the starch granules was unimodal. The distribution of the granules size ranged from 4.63-50.96 μm in the proximal tuber parts during the post-crops storage. As for distal tuber parts, it ranged from 4.56-44.71 μm. Otherwise, the results also showed that the average diameters of the granules appear significant (p<0.05) from one tuber part to another and during the post-crops storage. They all decreased during the storage. The proximal tuber parts had the highest size of the granules (Ø = 24.37-30.71 μm). Among the two studied cultivar, the parts of "Florido" cultivar presented the highest size of starch granules.