Starch Modification / Molecular Properties

Starch as a paper additive

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Modified starches with barrier properties

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Thermoplastic starch

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Carrier systems for food and pharmaceutical industry

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Modified raw materials containing starch

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Starch derivatives for adhesives and binders

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Starch Modification / Molecular Properties

Taylor-made starch

Starch is one of the most important renewable resources. Worldwide, more than 60 million tons are produced annually. Thereof, about 9.4 million tons are manufactured in Europe, and additionally, further amounts are imported. About 60 percent of starch and starch products are used in food and beverage sector. In the non-food sector, the paper industry is the main consumer. In addition, starch products are used in cosmetics and pharmaceuticals, fermentation, bioplastics, adhesives, building materials, sizing or cleaning agents.

In the department Starch modification / Molecular properties starch and starch products for industrial applications are modified and optimized. Our projects result from the industry's needs. On request, we adapt the renewable resource specifically to processing processes and applications. The special properties of starch − water solubility, water binding and viscosity properties − is just as important as its inhibiting swelling power and the limited water vapor permeability of films. Furthermore, the replacement of synthetic organic polymers on the basis of modified starch offers numerous advantages: the production processes are environmentally friendly and reduce harmful environmental influences.

Our services

The use of various technologies such as batch and pressure reactors, kneaders or extruders form the basis of our work. The processing and use of starch products is carried out with different methods of dispersion and solution preparation, in which the jet-cooking under industrial conditions should be emphasized.

 

Special experiences are available for the following modifications

  • physical modification for production of swelling starch
  • enzymatic modification with α-amylase, β-amylase and debranching enzymes to optimize the chemical structure
  • chemical modification
  • production of dextrins with acids or oxidising agents
  • crosslinking of starch for increasing the stability of aqueous dispersions against shearing, high temperatures and low pH values
  • starch ether
    The etherification can be carried out with reagents which  introduce neutral, cationic, anionic or hydrophobic substituents in the anhydroglucose unit. These substituents determine the functionality of the starch product.
  • starch esters
    Starch acetates belong to the most important esters. Low degrees of substitution change the swelling in water and reduce the tendency for retrogradation of starch. Starch acetates with high DS values ​​of 2-3 can be used in plastics.

Our research topics

Starch research - powerful products

Optimization of starch products for the adsorption on paper fibers is a focus of our work. The exploration of new possibilities for modification of starch as well as for bringing innovations in the starch industry and in the chemical manufacturing sector belong to the future-oriented tasks. It should be emphasized that the properties of modified starches not only depend on the type of modification, but also on the commodity itself, the composition of the starch granule, its partial crystallinity and the content of impurities affect not only physical characteristics but also the physical, enzymatic and chemical modifiability. Both, starch grains and certain swelling conditions can be the basis for the process development for modification of starch.

Methods for analysis and characterization of starch products

Parameter

Method


Analysis

amylose content amperometric titration of aqueous starch solutions
protein content
nitrogen determination by elemental analysis
phosphor content ICP
lipid content
solvent extraction


Properties of the starch granule

morphology light and scanning electron microscopy
particle size distribution diffraction of red laser light on aqueous suspensions
crystallinity X-ray wide angle scattering
solubility as a function of solvent, concentration, stirring intensity and temperature  


Chemical structure

molecular weight distribution and average molecular weight gel permeation chromatography with concentration and multi-angle laser light scattering detection (GPC-MALLS)
particle size distributions in the nanometer range dynamic light scattering
degree of substitution, substituent distribution
high-resolution 13C- and 1H-NMR


Rheological properties

 
Viscosity as a function of the shear stress Measurement of the flow behavior and dynamic rheology
Changes in solution structure as a function of concentration, temperature, time Measurement of the flow behavior and dynamic rheology
Low molecular weight substances Measurement of the flow behavior and dynamic rheology
Examination of the gel formation and characterization of gel properties Measurement of the flow behavior and dynamic rheology