According to Hu et al. (2009), native potato starch film has high tensile strength because of its high molecular

weight, which causes the paste of the native potato starch to have a high viscosity. Therefore, it is impossible to produce potato starch paste with high starch content because it would result in a lower efficiency in film-making. Moreover, the transparency of native potato starch paste is poorer than that of oxidised potato starch. Therefore, these authors chose oxidised potato starch to prepare edible film because it has a lower viscosity and higher transparency than native potato starch film. However, no Tenofovir ic50 previous studies have been reported on the production of edible and biodegradable films made from potato starch oxidised with sodium hypochlorite or treated with heat and moisture. The oxidation and hydrothermal treatment promotes a lower viscosity of starch, which is important for the development of potato starch film. The objective of this study was to evaluate the effect of oxidation with

sodium hypochlorite and HMT on the physicochemical, pasting and textural properties of potato starches in addition to the WVP and mechanical properties of oxidised and HMT potato starch films. Potatoes from the Baronesa (Solanum tuberosum L.) cultivar were used. Potato starch was isolated according to the method described by Liu, Weber, Currie, and Yada (2003). Potato samples were dehulled and soaked CDK inhibition in 0.1% sodium bisuphite at a 1:7 (w/v) ratio for 2 h after the dispersion was ground in a blender (Britania, Brazil) for Aprepitant 5 min, passed through a 63-μm screen and decanted. The starch was washed a minimum

of three times with distilled water and dried at 40 °C until the moisture content of the samples reached approximately 12%. The amylose content of the native potato starch was determined using the method proposed by Juliano (1971), and the amylose content of the native potato starch was determined to be 22.03%. The oxidation of potato starch was performed as previously described by Dias et al. (2011). The starch (300 g and 12% moisture) was suspended in 500 ml of distilled water, heated to 40 °C and subjected to sodium hypochlorite treatment with 0.5% active chlorine. The pH value was adjusted to 7.0 with 0.5 M hydrochloric acid and 0.5 M sodium hydroxide. After 60 min of reaction, the starch was withdrawn from the reactor, filtered through medium porosity filter paper in a Buchner funnel, washed with 1200 ml of distilled water, resuspended in distilled water and refiltered three times. The oxidised starch was dried in a forced air oven at 40 °C until the starch retained approximately 12% moisture. The HMT of the potato starch was performed on the samples with moisture levels adjusted to 20% and equilibrated at 4 °C overnight. The samples were then placed in sealed glass tubes and autoclaved at 110 °C for 1 h (Hormdok & Noomhorm, 2007).