Effects of incorporating nonmodified sweet potato (Ipomoea batatas) flour on wheat pasta functional characteristics

The effects of substituting wheat flour using fractions of blanched or nonblanched sweet potato flour on produced pasta functional characteristics were investigated. The use of sweet potato flour to replace fractions of wheat flour, regardless of blanching treatment, resulted in significant (p < .05) increase in water holding capacity (WHC), cooked pasta water uptake and solid leaching out and freeze-thaw stability of produced pasta. For instance, treatment containing 40% of nonblanched sweet potato flour and held at 55C resulted in 27% point increase in WHC compared to the control. Sweet potato flour was also contributed to the decrease in treatments pasting viscosities and in cooked pasta hardness. Cooked pasta hardness was significantly (p < .05) decreased from 255.6 N to 187.5, and 152.6 N when using 15% blanched and 40% nonblanched sweet potato flour replacements, respectively. Flow behavior index of wheat flour treatments containing fractions of sweet potato flour were fitted in a shear thinning model. Quality indices of pasta made using fractions of sweet potato were equivalent to or sometimes superior to that of the control sample. Results indicated the possible enhancement of pasta nutritional quality including firmness, cooking loss, and water uptake without impairing consumer acceptability.

The use of sweet potato flour in pasta would enhance the nutritional and physicochemical properties of developed pasta and pasta products. Furthermore, since sweet potato is not cultivated most of the year; sweet potato flour pasta would be better utilized in food processing and is expected to enhance sweet potato consumption year around.