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Phase and State Transitions and Transformations in Food Systems
Published in Dennis R. Heldman, Daryl B. Lund, Cristina M. Sabliov, Handbook of Food Engineering, 2018
Starch granules are insoluble in cold water, but they swell upon heating and crystallites become disordered. Starch gelatinization occurs during heating of starch-water mixtures. The gelatinization of starch also requires water, and the gelatinization temperature depends on water content. Water in the amorphous parts of starch acts as a plasticizer. This decreases the glass transition temperature of the noncrystalline regions of native starch and leads to melting of the crystalline parts as temperature is increased.
Ozone: An Advanced Oxidation Technology for Starch Modification
Published in Ozone: Science & Engineering, 2019
R. Pandiselvam, M.R. Manikantan, V. Divya, C. Ashokkumar, R. Kaavya, Anjineyulu Kothakota, S.V. Ramesh
The disruption of molecular orderliness within the starch granule is known as starch gelatinization. It results on the solubilization, swelling of granules, and development of viscosity. Different analytical techniques such as Differential scanning calorimetery (DSC), X-ray diffraction, Nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectroscopy have been employed to detect the gelatinization characteristics. Microscopic examination of granules undergoing gelatinization allows the observation of the degree and duration of swelling, as well as the integrity and size of the swollen granules. Starch gelatinization is an important property that varies with the composition (phosphorus, amylose to amylopectin ratio, proteins, lipids, etc.), the structure of amylopectin (extent of branching, unit chain length, molecular weight, the architecture of granule (crystalline to amorphous ratio), and the size distribution of starches (Kaur, Singh, and Singh 2005; Singh and Kaur 2004; Singh et al. 2003). Chan et al. (2012) reported that ozonation on starch molecules causes the oxidative cleavage and yields low-molecular weight molecules. These authors noticed that the pasting property of starch granules treated with ozone at 5°C for 1 h shows slight changes. The waxy rice flour and waxy rice starch granules gelatinization characteristics are attributed to surrounding for protein protection, which is hindered from oxidation by ozone led to no or slight change on gelatinization profile (Chan et al. 2012). The increase in ozonation time increases the starch gelatinization temperature (Catal and Ibanoglu 2014). The starch modified using ozone showed higher shear thinning behavior, less retrogradation tendency, and gelatinization percentage. It was concluded that starch modification can be carried out by application of ozone where greater cooking stability, low retrogradation ability, and reduced gelatinization characteristics are desirable. Ibanoğlu, Özaslan, and Ibanoğlu (2018a) observed the increases in gelatinization properties and decreases in gelatinization enthalpy of potato starch modified by ozone. The index of consistency and viscosity of ozonated potato starch samples found no differences and also no effect on flow properties. Similar results have been found for rice, corn, and wheat starches modified using ozone (Ibanoğlu, Özaslan, and Ibanoğlu 2018b; Catal and Ibanoglu 2014; Çatal and İbanoğlu, 2012). In contrast, Sandhu, Manthey, and Simsek (2012) and Goze et al. (2016) reported that starch gelatinization profile (temperature of gelatinization and enthalpy) of wheat flour and wheat grains was not significantly affected by ozone treatment.