Quality evaluation of noodles partially substituted with white- and purple-fleshed sweet potato flours

Abstract

In this study, noodles were produced by replacing a portion of wheat flour with a combination of white-fleshed sweet potato (WFSP) flour at 3%, 4.5%, 6%, 7.5%, and 9%, and purple-fleshed sweet potato (PFSP) flour at 10%, 12.5%, 15%, 17.5%, and 20%. The results indicated that the noodles exhibited the highest quality in terms of physicochemical properties and nutritional composition when formulated with WFSP and PFSP flour contents of 7.5% and 17.5%, respectively, which involved partial substitution of wheat flour. The cooking quality of the noodles was assessed through parameters such as weight increase, volume increase percentage, and cooking loss, all of which showed favorable outcomes under these conditions. The noodles contained high levels of anthocyanins and total polyphenols, measuring 82.80 mg/100 g and 18.94 mg GAE/g, respectively, along with the characteristic purple coloration derived from PFSP. When sweet potato flour was used to partially replace wheat flour, the estimated potential renal acid load (PRAL) score was reduced to 4.38 compared to the control sample, which was made entirely of wheat flour and had a PRAL score of 11.75. Nutritional analysis revealed that the noodles contained protein at 8.19%, carbohydrates at 16.45%, fat at 1.17%, moisture at 63.32%, fiber at 2.52%, ash at 0.65%, and resistant starch at 4.11%. Therefore, incorporating sweet potatoes, which are rich in nutrients, into product processing is significant for nutrition, economic benefits, and sustainable development.