Physical Modification of Food Starch Functionalities

Abstract

Because, in general, native starches do not have properties that make them ideally suited for applications in food products, most starch is modified by dervatization to improve its functionality before use in processed food formulations, and because food processors would prefer not to have to use the modified food starch label designation required when chemically modified starches are used, there is considerable interest in providing starches with desired functionalities that have not been chemically modified. One investigated approach is property modification via physical treatments, that is, modifications of starches imparted by physical treatments that do not result in any chemical modification of the starch. Physical treatments are divided into thermal and nonthermal treatments. Thermal treatments include those that produce pregelatinized and granular cold-water-swelling starches, heat-moisture treatments, annealing, microwave heating, so-called osmotic pressure treatment, and heating of dry starch. Nonthermal treatments include ultrahigh-pressure treatments, instantaneous controlled pressure drop, use of high-pressure homogenizers, dynamic pulsed pressure, pulsed electric field, and freezing and thawing.

Effect of high hydrostatic pressure in physicochemical properties and in vitro digestibility of cornstarch by nuclear magnetic resonance relaxometry

“…One of the differences was the shear forces (i.e., stirring) applied during conventional heating of a starch suspension. Stirring provoked granule disintegration, which was an absent incident in starch gelatinization by HHP (BeMiller & Huber, ).…”

Microwave absorption capacity of rice flour. Impact of the radiation on rice flour microstructure, thermal and viscometric properties

“…The conditions of typical HMT processes (high moisture, high temperature, long time) afford increased mobility to the starch chains and helical structures, resulting in structural changes in both the crystalline and amorphous regions of the starch granules. This mobility allows the disruption of the least stable structures of crystalline regions, altering organization of highly ordered helical structures and/or crystallites within granules (BeMiller & Huber, 2015). However, MWT, due to much faster and uniform heat distribution as well as local superheating points and the loss of water during the process, can lead to other structure rearrangements reflecting in higher final crystallinity.…”

Effects of heat–moisture, autoclaving, and microwave treatments on physicochemical properties of proso millet starch

“…Microwave treatment (MT) affects starch through dielectric heating and electromagnetic polarization effects (Bilbao‐Sáinz, Butler, Weaver, & Bent, ). Modification alters the starch physicochemical properties and can improve the functionality of native starch (Bemiller & Huber, ). Previously reported studies of proso millet starch have focused on crop breeding and genotype (Wang et al, ), or comparing the physicochemical properties of different varieties (Wang et al, ).…”