Physicochemical properties of twenty-one Caribbean sweet potato cultivars

The physical, chemical and physicochemical properties of twenty-one Caribbean sweet potato cultivars were investigated. Hunter L a b colour parameters were measured, chroma, colour intensity and hue angle were calculated. Proximate composition, vitamin C, amylose, reducing and non-reducing sugars contents were determined using standard methods. Pasting properties were determined using Rapid Visco Analyser. Tuber size (length, r  = 0.72, n  = 21, P  < 0.0015; width, r  = 0.85, n  = 21, P  < 0.0002) was highly correlated with weight of the tubers. External colours of the tubers ( L =  28.7–63.1, a =  +5.9 to +18.0, b =  +3 to +19.3) were lower than the flesh colours ( L =  60.8–84.0, a =  −2.4 to +27.8, b =  +9.9 to +28.5). Proximate composition is typical of sweet potato cultivars but significant differences exist among cultivars. Total sugar, amylose and amylopectin contents ranged from 1.8 to 4.7%, 15.3–31.2% and 68.8–84.7%, respectively. Cooking profiles of the sweet potato flours showed similar trend. Pasting temperature, peak time, swelling power and solubility ranged from 78.3 to 93.0 °C, 3.3–4.8 min, 5.6–23.5 and 11.7–45.7%, respectively.