title: Relationship between the physicochemical properties of starches and the glycemic indices of some Jamaican yams (Dioscorea spp.).
abstract: Starch granules from round leaf yellow yam (RY), Lucea yam (LY), white yam (WY), and Chinese yam (CY) grown in Jamaica were isolated and the relationship between starch amylose content, crystallinity, microscopic properties, in vitro digestibility, and the glycemic index (GI) of the tubers was investigated. The results indicate that RY had the highest amylose content (265.30 +/- 0.09 g/kg starch) while CY the lowest (111.44 +/- 0.03 g/kg starch). A corresponding variation in starch digestibility and GI was also observed, as CY which had the highest in vitro digestibility had the highest GI (21.27 +/- 0.01 and 97.42 +/- 0.62%, respectively), while RY, LY, and WY starches with low digestibility had lowest GI. Differences in the crystalline pattern of the different starches were observed, where RY, LY, and WY displayed the type B crystalline pattern while CY had the intermediate crystallite (type C).
authors: Biotechnology Centre, University of the West Indies, Jamaica, West Indies.
authors: Cliff K
authors: CK
authors: Riley
authors: Perceval S
authors: PS
authors: Bahado-Singh
authors: Andrew O
authors: AO
authors: Wheatley
authors: Mohammed H
authors: MH
authors: Ahmad
authors: Helen N
authors: HN
authors: Asemota
mesh_terms: D000688:Amylose / Q000032:analysis; D001786:Blood Glucose / Q000378:metabolism; D003594:Cytoplasmic Granules / Q000737:chemistry / Q000648:ultrastructure; D004040:Dietary Carbohydrates / Q000032:analysis; D004063:Digestion; D027742:Dioscorea / Q000737:chemistry*; D038321:Glycemic Index; D006801:Humans; D007563:Jamaica; D018517:Plant Roots / Q000737:chemistry; D013213:Starch / Q000032:analysis* / Q000302:isolation & purification
chemical_list: D001786:Blood Glucose; D004040:Dietary Carbohydrates; D013213:Starch; D000688:Amylose