Structure-related properties of sweetpotato critically impact the textural quality of fried chips

This study sought to define what attributes of sweetpotatoes are most critical to textural qualities of their fried chips for effective selection of specialty cultivars. It compared texture-predicting fracturability of fried chips prepared from either structurally intact or disrupted slices of 13 cultivars; analyzed major attributes of these sweetpotatoes, including starch contents and properties, dry matter contents, and structure-related penetration resistances (measured using an adapted penetration test); and evaluated correlational relationships between these attributes of sweetpotatoes and fracturability of fried chips. The study found that lower dry matter (<22.6% F.W.) and starch contents (<10% F.W.), and lower gelatinization temperatures of starch in sweetpotatoes generally resulted in a more favorable fracturability (lower peak break force) of fried chips. However, contrary to potato, total dry matter content is not the sole determinant of textural qualities of fried sweetpotato chips; instead, structure-related attributes of sweetpotatoes appear to have a greater impact. Partial structural disruptions of sweetpotato slices by blanching effectively improved fracturability of fried chips in all analyzed cultivars, and by ~40% in eight of the 13 cultivars. Furthermore, the degree of structural penetrability of sweetpotatoes, as indexed by penetration resistances, showed very significant correlations with fracturability of fried chips.   Key words: Sweetpotato chips, fracturability, puncture test, structure-related attributes, dry matter content, starch.