Carbohydrate Changes in Sweet Potatoes During Curing and Storage

The quantity and pattern of carbohydrate change during curing and storage differed among 6 sweet potato [ Ipomoea batatas (L.) Lam] cultivars. ‘Travis’ contained the most total sugar and ‘Whitestar’ the least on a dry weight basis. Sucrose, the major sugar in raw sweet potatoes, sharply increased during curing (10 days at 32°C; 90% RH), and generally continued to increase in 4 orange-flesh cultivars during 46 weeks of 15.6° storage. Sucrose concentration decreased in 2 white-flesh cultivars after curing, followed by an increase after 14 weeks of storage. Glucose concentration was slightly higher than fructose in all cultivars except ‘Centennial’, which had similar monosaccharide concentrations. The pattern of monosaccharide change during curing and storage varied with cultivar, but generally increased during curing and the first 4 weeks of storage, followed by stabilization or a slight increase. Alcohol-insoluble solids (AIS) decreased with increasing lengths of storage in the 4 orange-flesh cultivars, which was attributed to continuous starch degradation. AIS increased during the first 4 or 14 weeks of storage in the 2 white-flesh cultivars, followed by a decrease during longer periods of storage.