Development of Instant Fried Noodles Made from Composite Flour of Wheat and Sweet Potato Flours

Abstract

Orange, purple and yellow-fleshed cultivars of sweet potato were prepared to make uncooked (UC) and cooked (C) sweet potato flour. Different preparations of sweet potato flour were used to replace wheat flour in the production of instant fried noodle production. To determine the physicochemical properties and acceptability of instant fried noodles, different percentages (20, 30, 40%) (w/w) of each sweet potato flour sample were used. Total dietary fiber, antioxidant activity, total phenolic content and textural qualities of instant fried noodles were determined. The instant fried noodles with 40% replacement of sweet potato flour with each cultivar increased total dietary fiber more than 10% of the Thai recommended daily intake (RDI). The instant fried noodle with added purple-fleshed sweet potato flour had the highest antioxidant activities, which ranged from 8.27 ± 0.66 to 17.81 ± 0.42 mg vitamin C equivalent (VCE)/100 g, which compared to wheat noodles (3.61 ± 0.07 mg). The total phenolic content was in the range of 38.29 ± 0.81 to 55.58 ± 1.27 mg of gallic acid equivalent (GAE) per 100 g noodles, which was similar to wheat noodles (32.09 ± 0.31 mg). The tensile force and breaking distance of instant fried noodles containing uncooked sweet potato flour of each cultivar were significantly greater than for noodles containing cooked sweet potato flour (p ≤ 0.05). The tensile force and breaking distance of instant fried noodles containing 20% uncooked purple-fleshed sweet potato flour were not significantly different from wheat noodles (p ≥ 0.05). The sensory acceptability of instant fried noodles made with 20% sweet potato flour from each cultivar had the highest overall liking scores.