Water content influence on thermal and volumetric properties of wheat starch gelatinization under 10 MPa

Abstract

A transitiometric in situ analysis of wheat starch aqueous suspensions heated over a temperature range from 285 K to 415 K under isobaric conditions of 10 MPa is presented. Measurements were performed at four selected water concentrations: 56.0%, 64.7%, 73.5%, and 82.4% weight/water. Thermal and volumetric properties and their water content dependencies have been determined for three successive starch phase transformations occurred during wheat starch gelatinization.

Phase Transitions of Pea Starch over a Wide Range of Water Content

“…During gelatinization, starch granules take up water and swell, concomitant with a series of changes such as loss of birefringence, melting of crystallites, unwinding of amylopectin double helices, loss of granular morphology, and solubilization of some of the starch molecules. − Differential scanning calorimetry (DSC), which provides a means for the quantitative analysis of thermal transition parameters, has been widely applied to monitoring starch gelatinization. Donovan first studied the influence of water content on phase transitions of potato starch using DSC, and subsequent studies have presented similar DSC thermograms of starch–water systems at similar water content. ,, At around 50% water content, two overlapping endotherms (referred to as endotherms G and M1) are observed, and then at higher temperature a third endotherm is usually observed to overlap with an adjacent following exotherm. Increasing water content above 50% results in a progressive convergence of endotherms G and M1, whereas decreasing water content below 50% leads to the gradual disappearance of endotherm G and the shifting of endotherm M1 to higher temperatures.…”

“…Donovan first studied the influence of water content on phase transitions of potato starch using DSC, 14 and subsequent studies have presented similar DSC thermograms of starch−water systems at similar water content. 11,15,16 At around 50% water content, two overlapping endotherms (referred to as endotherms G and M1) are observed, and then at higher temperature a third endotherm is usually observed to overlap with an adjacent following exotherm. Increasing water content above 50% results in a progressive convergence of endotherms G and M1, whereas decreasing water content below 50% leads to the gradual disappearance of endotherm G and the shifting of endotherm M1 to higher temperatures.…”

Effect of water content on gelatinization functionality of flour from sprouted sorghum

“…To the best of our knowledge, there are no studies focusing on the gelatinization properties of sprouted sorghum over a wide range of water contents. Such investigations have been carried out in the last 20 years for different starch sources, such as pea starch ( Wang and Copeland, 2012 ), waxy corn, normal corn, potato and pea starches ( Tananuwong and Reid, 2004 ), corn starch ( Fu et al, 2014 ), potato dry matter and starch ( Liu et al, 2002 ), and wheat starch ( Orlowska and Randzio, 2010 ). The present study was undertaken to better understand the physicochemical properties and the gelatinization behavior of water-flour systems of sprouted and unsprouted sorghum flours.…”