Characterisation of starches from West African yams

Abstract

Starches from four varieties of West African yams were extracted and characterised. The physicochemical properties investigated (granule size and morphology, amylose content, crystal form, gelatinisation and pasting behaviour) depended strongly on the yam variety. The starch granules extracted from water yam (Dioscorea alata), white yam (D rotundata) and yellow yam (D cayensis) varieties showed mononodal particle size distributions centred between 31 and 35 mm, while the bitter yam (D dumetorum) exhibited a binodal size distribution of starch granules centred at 4.5 and 9 mm. Light microscopy con®rmed the variation in starch granule size and shape with yam variety. The X-ray diffractogram of yellow yam was of the B type, while bitter yam showed an A pattern. The starches extracted from the white and water yams were of the intermediate C-type patterns. The temperatures of onset of gelatinisation were derived from DSC and RVA measurements; values of 69.4 and 75.0°C for the yellow yam, 71.5 and 78.2°C for the white yam, 76.5 and 79.8°C for the water yam and 78.1 and 83.1°C for the bitter yam were obtained.

Effect of water content and mucilage on physico-chemical characteristics of Yam (Discorea alata Purpurea) starch

“…1). This observation was similar to those for D. alata (Farhat et al, 1999) and Japanese yam (Sugimoto et al, 1986), but different from elliptic and oval shapes of Dioscorea opposita Thunb var. Zhongbowen starch (Wang et al, 2007) and the oval shape of Discores nipponica Makino (Yuan et al, 2007).…”

Studies on tuber and root starches. I. Structure and physicochemical properties of innala (Solenostemon rotundifolius) starches grown in Sri Lanka

“…The DH of both Bola and Dik were higher than those reported for genotypes of sweet potato (12.9 J/g, Collado et al, 1999), potato (14.9 J/g, Ganga & Corke, 1999), taro (6.8 J/g, Jane et al, 1992), but lower than that reported for genotypes of yam (19.8 J/g, Farhat et al, 1999). The gelatinization characteristics of many other tuber starches have been determined by Kofler hot stage microscopy.…”

Physico-chemical properties of edible films derived from native and phosphated cush-cush yam and cassava starches

“…f o o d p a c k a g i n g a n d s h e l f l i f e 3 ( 2 0 1 5 ) 1 -8 conformations are disrupted by the formation of stable single chain V-conformation helices resulting in the glycerol-amylose complex (Farhat, Oguntona, & Neale, 1999;Manzocco, Nicoli, & Labuza, 2003;Zobel, 1994). As can be seen in Fig.…”