DP profile determination (DP characterization)

The determination of the DP polymerization profile , also called characterization of the degree of polymerization (DP) , makes it possible to evaluate the average length of the chains constituting a polymer or a polysaccharide. This structural parameter is decisive for understanding the physicochemical behavior, stability and functional properties of the materials or extracts analyzed.

The analysis is carried out by GPC (gel permeation chromatography) or SEC (size exclusion chromatography) , two reference techniques for the characterization of the molecular size and mass distribution of natural or synthetic polymers.

Degree of polymerization: a key indicator of molecular structure

The degree of polymerization (DP) represents the average number of repeating units (monomers) constituting a polymer or polysaccharide molecule. The higher the DP, the longer the molecular chain and the more its physical properties—viscosity, solubility, elasticity, or crystallinity—are modified.

This parameter is crucial for:

• assess the quality of natural polymers (starch, cellulose, pectin, inulin, chitin),
• determine the level of hydrolysis or degradation of the chains,
• correlate molecular structure with functional performance (gelation, thickening, solubilization),
• compare the stability or biodegradability of technical or bio-sourced polymers.

In the field of food polysaccharides , the DP makes it possible to distinguish, for example:

• simple sugars (DP = 1),
• oligosaccharides (DP from 2 to 10),
• complex polysaccharides (DP > 10).

This distinction is essential in studies of digestibility, glycemic index or functional formulation.

Objectives and interest of the DP profile dosage

The characterization of the DP profile allows:

• determine the average chain size and their molecular mass distribution ,
• assess the purity and level of degradation of a polymer,
• monitor structural changes linked to thermal, enzymatic or chemical treatment,
• control the consistency of formulation between production batches,
• validate the functional performance of ingredients or materials based on natural polymers.

The main matrices concerned are:

• starch and derivatives (amylose, amylopectin, maltodextrins),
• fibers and pectins ,
• gums and mucilages (guar, arabic, xanthan),
• functional oligosaccharides ( inulin, FOS, GOS),
• bio-sourced or technical polymers ( PLA, PVA, polyacrylates).

Analytical methods used

DP profile measurement is mainly based on size exclusion chromatography (SEC) or gel permeation chromatography (GPC) . Both methods separate molecules based on their hydrodynamic size, without chemical interaction with the stationary phase.

Samples are dissolved in a suitable solvent and injected into a gel column calibrated to standards of known molecular mass. Detection is carried out by:

• refractometry (RI) for most polysaccharides,
• UV/Vis detection for absorbent polymers,
• light scattering detection (MALLS) for absolute molecular mass measurement.

The molecular weight distribution curve (Mw, Mn, PDI) allows the calculation of the average degree of polymerization (DPn) and the dispersion of the chain size.

In some cases, the analysis may be supplemented by:

• chromatography (HPAEC-PAD) for short oligosaccharides,
• NMR spectroscopy to confirm structural patterns,
• spectroscopy (FTIR) to identify associated chemical functions.

YesWeLab selects the most suitable method based on the polymer type, purity level and analytical objectives of the customer.

Industrial and regulatory applications

The dosage of the DP profile is essential in many sectors:

• Food and nutrition : it allows the characterization of food polysaccharides (starch, inulin, pectin) in order to predict their digestive behavior, their viscosity or their prebiotic role. This data is notably used to estimate the hydrolysis rate and the glycemic potential of complex carbohydrates.
• Nutraceutical : Plant extracts or functional fibers are analyzed to ensure reproducible composition and stable physiological activity.
• Animal nutrition : DP measurement allows the fermentability and digestibility of carbohydrate-rich ingredients to be assessed.
• Bio-based materials and polymers : In the field of bioplastics and biodegradable materials, DP directly influences mechanical strength, transparency and thermal stability.

This analysis can be associated with additional services such as:

• Starch and gelatinization determination,
• Analysis of the sugar profile by HPLC,
• Characterization of polymers by GPC,
• Infrared spectroscopy (FTIR)

Carrying out analyses at YesWeLab

YesWeLab relies on a network of partner laboratories specialized in the molecular and macromolecular characterization of polymers and polysaccharides. These laboratories have GPC/SEC equipment coupled with multi-angle detectors, guaranteeing accurate DP measurement over a wide range of molecular masses.

Testing is carried out according to good laboratory practices and in compliance with ISO 17025. Protocols can be adapted to customer specifications, whether for quality control, R&D study or regulatory validation.

Since 2020, YesWeLab has been supporting players in the food, nutraceutical and polymer materials industries in mastering their formulations and the advanced characterization of their ingredients.

Thanks to its digital platform, manufacturers can centralize their analysis requests, track their samples and access their technical reports securely.

Technical data

• Methods: GPC, SEC, HPAEC-PAD
• Expertise: Physicochemical
• Sectors of activity: Human food, nutraceuticals, animal nutrition, polymers
• Measured parameters: Degree of polymerization (DPn), average molecular weight (Mw, Mn), polydispersity index (PDI)
• Normative references: ISO 17025, validated internal methods

For any specific request, contact our team to obtain a personalized quote and analytical advice adapted to your matrix and your formulation or quality control objectives.