Techniques Rapidly Developed in Starch Modification

Starch is routinely used in pharmaceutical, papermaking, food, and other industries, but some natural characteristics of native starch (degradation and gelatinization problems, instability at high temperature and acid conditions, etc.) limit its practical application.

On the basis of achieving the desired modification degree, it is particularly important to select an appropriate modification method. Vast technologies have been investigated, among which the non-thermal physical modification technology has attracted enhancive attention due to its environment-friendly and high product safety characteristics. The technology will not modify D-glucopyranosyl units of starch polymer molecules, except for the breaking of some glycosidic bonds. Non-thermal physical modification methods include ultrahigh-pressure treatment, instantaneous controlled pressure drop, pulsed electric field, dynamic pulsed pressure, freeze-thaw process, gamma-irradiation, etc. The application of these techniques has increased the selection of starch modification schemes.

Fig.1 Non-thermal physical modification techniques and their impact on starch granules. (Wu, et al., 2022)

Non-Thermal Physical Modification Service

This technology can effectively adjust starch specialties and improve its applicability. CD BioGlyco provides a variety of advanced non-thermal physical modification solutions for customers to choose from.

• Microwave Treatment: Microwave energy can produce electric and magnetic fields with spectral rates between 300 and 300,000 megahertz. When starch is exposed to a microwave, polarized or charged atoms tend to align with components of the microwave electric field, rapidly changing the direction of the microwave. Microwave modification mainly depends on the rapid dipole relocation of starch polar molecules caused by dielectric heating.

Fig.2 Mechanism of Microwave Treatment. (Suri & Singh, 2023)

• High Hydrostatic Pressure (HHP): HHP treatment is also referred to as cold gelatinization. It can make starch gelatinize under simpler conditions, resulting in partial disintegration of starch particles, changes in crystalline structure, and a decrease in solution viscosity.

Fig.3 Mechanism of High Hydrostatic Pressure processing. (Suri & Singh, 2023)

• Pulsed Electric Field (PEF): PEF treatment modifies starch in an ultra-short time (microsecond) through a high-intensity electrical pulse to change the granule morphology, increase the roughness, form cracks and holes on the surface, and reduce the crystallinity, gelatinization enthalpy, and viscosity of starch. The process can change the content of digestible starch and maintain the content of resistant starch.

Fig.4 Mechanism of Pulsed Electric Field processing. (Singh, et al., 2022)

• Gamma-Irradiation: It changes the structure of starch granules by generating free radicals, but does not cause significant changes in the morphology of particles, except for a few cracks or holes on the surface. Relative crystallinity, swelling capacity, and viscosity decrease with increasing radiation dose.

Fig.5 Possible alteration of starch chains influenced by Gamma Irradiation. (Kong, 2018)

Applications

• Continuous and large-scale production of physically modified starch with specific properties
• Food industry development: Better organoleptic and nutritive properties

Highlights

• Optional non-thermal physical modification methods
• Safety, environmental friendliness, and cost-effectiveness
• Without generating chemical wastes

CD BioGlyco also provides other Physical Modification services of starch, as well as Chemical Modification, Enzymatic Modification, and Genetical Modification services. If you are interested in our services, please contact us for more information and we will be with you soon.

• Pre-Gelatinization
• Annealing (ANN)
• Heat-Moisture Treatment (HMT)
• Cold Plasma Treatment