Abstract

Physiochemical Properties of Sweet Potato and Mung Bean Starch and Their Blends for Noodle Production

Ho Minh Thao and Athapol Noomhorm

Physiochemical properties of four types of sweet potato starch (SPS) and mung bean starch (MBS), and their blends for noodle production were accessed. The results indicated that MBS was significantly higher in amylose content (40.69%), gel hardness, hot paste stability and cold paste viscosity; but substantially lower in protein, lipid, ash content, and gel stickiness than those of all sweet potato starches. Among all sweet potato varieties, the white skin and yellow-red flesh color sweet potato variety (SP1_W_YR) was the most suitable for noodle production due to its the highest starch yield (17%) and starch purity as well as the best starch color. The MBS noodle quality was superior to SPS noodle quality, and blending SPS with MBS for noodle production resulted in markedly reducing quality. However, the quality of noodles made from mixture of 20% SPS and 80% MBS was not significant difference to that of MBS noodles. The increase of solid content of starch slurry resulted in considerable increasing in cooking time, cooking loss, rehydration and tensile of noodles while aging time only markedly affected cooking loss and tensile. For noodles prepared from mixture of 20% SPS and 80% MBS, the most suitable initial solid content of starch slurry and aging time at 4 o C were 35% and 10-20 hrs respectively.