Studies on Some Important Consumer and Processing Traits for Breeding Sweet Potato for Varied End-uses

Aims: To determine; (1) the variability among the elite sweet potato lines for root processing quality traits; (2) the heritability of each trait and the correlation among them; (3)the acceptability of the boiled and fried roots by sweet potato consumers; and (4) an easy-to-measure traits that are linked to consumer acceptability of sweet potato roots.

Study Design: Completely randomized design with three replications.

Place and Duration of Study: The National Root Crops Research Institute, Umudike, Nigeria.

Methodology: Fourteen advanced sweet potato lines were evaluated for processing traits such as dry matter, starch yield, flour yield, peel-loss, and total carotenoid. Correlation analysis among the traits was carried out, and broadsense heritability for each trait was calculated. Sensory evaluation was carried out on roots of the lines using selected panelists. Culinary traits that most influenced acceptability of boiled and fried sweet potato roots were determined using forward selection multiple regression analysis.

Results: There was significant (P=.05) variation among the 14 advanced lines for dry matter, starch content, flour content and peel loss. Dry matter ranged between 24.16 and 34.17%, starch content between 17.58 and 22.0%, flour yield between 21.34 and 32.32% and peel loss between 18.17 and 24.01%. Correlation studies showed that dry matter had significant (P<0.05) correlation with starch and flour yield. There were significant (P<0.05) differences among the genotypes for root colour and general acceptability for boiled roots, and root colour, mouth-feel, taste, aroma and general acceptability for fried roots. Forward selection multiple regression analyses for boiled and fried sensory traits identified fresh root colour as an easy-to-select trait to breed for consumer acceptability.

Conclusion: All the processing traits evaluated were heritable and most of them acceptable for boiled and fried food forms. The identification of root flesh colour as an easy-to-measure trait that influences consumer acceptability is a major achievement of this work