Résumé
Yam is a significant economic and ceremonial crop in Nigeria, however despite producing about 68% ofthe world's annual total products ofYaITIs, Yam consumption and utilization in the country is limited to a narrow range of foodproducts leading to sorne volatility of demand and instability of profit margin to resource poor farmets~The study was done to investigate the physicochemical and rheological properties of yam statchè'si forpotential industrial utilization. Starches were isolated from 16 varieties of yam fram' 1EY.', "rotundata, D. alata, D. bulbifera, and D. dumetorum. Microstructure and particle site'ooé[~is was studied. Rheological properties (G' and G", tan a) of the starch gels were smdied lbY. ~tna~' dfâ,lrheotneter. Thermal properties of the starches were investigated by DiffetëntiEil. ~camÎ1!tgdal()rimetry.· Digestibility of the starches was studied using termamyl (a-amylase).-Theshape of the starcb granules of D.rotundata and D.alata were mostly oval and eUipsoidal, D.bulbifera:· triangular, D.dumetorum: polyhedral. Mean granule size of D.alatawas 29.39 flm, D.rotundata; 29.64 Jlm), D.bulbifera; 24.60 Jim and D.dumetorum; 3.1 Jlm. D. rotundata starches had the highest storage modulus and greater tendency to form elastic gels compared to other species, it also exhibited higher enthalpy of gelatinization and transition temperature implying higher crystallinity and resistant to gelatinization. D.dumetorum starch was the most digestible among the yam starches while D. bulbifera was the least this may iInply high quantity ofresistant starch. Variability in these properties among the yam starches indicate that they can have wide applications in both food and non-food industries. ( Résumé d'auteur)