Content of Alpha-, Beta-Carotene, and Dietary Fiber in 18 Sweetpotato Varieties Grown in Hawaii

Eighteen commercial varieties of sweetpotato roots grown in Hawaii were harvested in spring and fall and analyzed for their nutrient compositions. The HPLC analysis of carotenoids showed lower beta-carotene content (13.1 mg/100 g fresh weight) in orange fleshed varieties than counterparts analyzed in mainland U.S.A. The beta-carotene content in light yellow and purple fleshed ones were in the range of 0.1–0.6 mg/100 g, fresh weight. Alpha-carotene was positively identified in two varieties with Hawaii origins at 0.3 and 1.5 mg/100 g fresh weight, respectively. The enzymatic–gravimetric method for the dietary fiber analysis revealed a substantial presence of the soluble fiber. The soluble fiber content in two purple fleshed varieties was approximately half of the total fiber content. Total fiber contents were in the range of 2.01–3.87 g/100 g fresh weight, higher than previously reported.