89 RVU) (Table 2). Li and Vasanthan (2003) also observed the same behaviour in the pasting properties when field pea starches are oxidised with sodium hypochlorite. Sangseethong, Termvejsayanon, and Sriroth (2010) evaluated the effect of reaction time in hypochlorite-oxidised and peroxide-oxidised cassava starches, and they reported that the viscosity of oxidised starches decreases with increasing reaction time. The decrease in viscosity of hypochlorite-oxidised and peroxide-oxidised starches can be attributed to the oxidative

cleavage of starch chains, which results in starch of a lower molecular size (Kuakpetoon & Wang, 2001). Wang and Wang (2003) reported that the pasting temperature of oxidised common corn starches is decreased and that the pasting temperature of oxidised waxy corn starches remains unchanged compared to the native starches. The HMT caused a significant decrease in pasting temperature, check details peak viscosity, holding viscosity, breakdown, final viscosity and setback (Table 2). The low values of viscosity observed for the HMT

starch may indicate a partial gelatinisation of starch due to the treatment conditions. The changes in the pasting properties of the heat–moisture treated starches are due to the associations among the chains in the amorphous region of the granule and the changes in crystallinity during hydrothermal treatment. The resistance of the hydrothermally signaling pathway treated starches to swelling is due to the rearrangement of internal forces, thereby, reducing swelling and stabilising the already swollen granules against mechanical fragmentation. The reduction of the breakdown caused by HMT suggested that the starches were more stable during continued heating and shearing, which was in agreement with a previous report by Hormdok and Noomhorm (2007) who found a reduction in the Dynein viscosity parameters of HMT rice

starch. Chung, Liu, and Hoover (2009) found that HMT reduces the leached amylose in the starch granules. This may explain the fact that hydrothermally treated starch causes a reduction in the setback because HMT promotes interactions between amylose–amylose and/or amylose–amylopectin chains which reduce leached amylose content and lower the setback. Hardness is a measure of texture that corresponds to the force applied to cause deformation of a sample and is measured by a texturometer. Gel hardness, springiness, cohesiveness and gumminess values of the oxidised and HMT potato starches are listed in Table 3. Compared to the native starch, the oxidative treatment with sodium hypochlorite increased the gel hardness of the potato starch, and the HMT decreased the gel hardness of the potato starch compared to the native starch (Table 3). Moreover, the springiness presented the same behaviour as the gel hardness. However, the cohesiveness and gumminess values were reduced for both modifications as compared to the native starch (Table 3).