Sugars and alcohol insoluble solids assessment for sweet potato cultivars recommended for Puerto Rico

Abstract

Sweetness-to-taste and starch content are critical quality attributes for the sweet potato root market in Puerto Rico. Current information in regard to these attributes for the cultivars accepted on Puerto Rico's market is not sufficient for establishing breeding standards and selection programs. The objective was to assess the sugar concentrations and crude starch for cultivars grown in Puerto Rico. From cultivars recommended for Puerto Rico, flours were prepared with raw, boiled and microwaved roots from which glucose, fructose, sucrose and maltose concentrations were determined by using high performance liquid chromatography (HPLC). After the sugar extraction, the insoluble solid fraction of the flour was used to determine the alcohol insoluble solids. Sucrose was the most concentrated sugar in the raw roots. Maltose concentration in boiled and microwaved roots was significantly higher than that in the corresponding raw roots. The alcohol insoluble solids for boiled and microwaved roots were significantly fewer than for raw roots. 'Miguela' should be considered the standard cultivar for sugar and starch content because it stands out with relatively high concentrations of sucrose and fructose, and with a reduced percentage of alcohol insoluble solids.