Modification of Rice Flour by Heat Moisture Treatment (HMT) to Produce Rice Noodles

Abstract

Modification of rice starch in flour from Chai Nat 1 cultivar by Heat Moisture Treatment (HMT) was evaluated for the physical and physicochemical characteristics in order to choose the modified flour to produce rice noodles. The moisture content of wet-milling rice flour was adjusted to 25%,
followed by heating at 110 or 120^oC for 1, 3 or 5 h to make the HMT flour. Pasting properties of native and HMT flour were evaluated by Rapid Visco Analyser (RVA). HMT120-5 flour had significantly (p ≤ 0.05) lower peak viscosity (136.50 RVU), trough (118.67 RVU), breakdown (17.83 RVU), final
viscosity (137.85 RVU) and setback (19.18 RVU) than those of native flour, while the pasting temperature of the modified rice flour (91.56^oC) was significantly (p ≤ 0.05) higher than that of native flour (80.80^oC). The swelling power of modified rice flour decreased at high temperature whereas solubility was not significantly different. At 90^oC, the swelling power of native and HMT120-5 flour were 12.25 and 8.93 g/g, whereas the solubility was 3.21 and 5.16%, respectively. This modification method changed HMT flour color by increasing the redness (a*) and yellowness (b*) when the holding time in hot air oven was increased. The noodles made from 10% HMT120-5 flour had higher tensile strength than the noodles made of unmodified rice flour.