DP profile assay (DP characterization)

The degree of polymerization (DP) profile analysis , also known as degree of polymerization (DP) characterization , allows for the evaluation of the average chain length of a polymer or polysaccharide. This structural parameter is crucial for understanding the physicochemical behavior, stability, and functional properties of the analyzed materials or extracts.

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.

The degree of polymerization: a key indicator of molecular structure

The degree of polymerization (DP) represents the average number of repeating units (monomers) that make up 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 altered.

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 (gelling, thickening, solubilization),
• compare the stability or biodegradability of technical or bio-based polymers.

In the field of food polysaccharides , DP allows us 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 benefits of DP profile testing

Characterizing the DP profile allows us to:

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

The main matrices involved are:

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

Analytical methods used

The measurement of the DP profile relies primarily on size exclusion chromatography (SEC) or gel permeation chromatography (GPC) . These two methods separate molecules according to their hydrodynamic size, without chemical interaction with the stationary phase.

The samples are dissolved in a suitable solvent and injected into a gel column calibrated to known molecular mass standards. Detection is performed by:

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

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

In some cases, the analysis can be supplemented by:

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

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

Industrial and regulatory applications

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

• Food and nutrition : it allows the characterization of dietary polysaccharides (starch, inulin, pectin) in order to predict their digestive behavior, viscosity, or prebiotic role. This data is notably used to estimate the hydrolysis rate and glycemic potential of complex carbohydrates.
• Nutraceutical : plant extracts or functional fibers are analyzed to guarantee a reproducible composition and stable physiological activity.
• Animal nutrition : the measurement of DP allows us to assess the fermentability and digestibility of carbohydrate-rich ingredients.
• 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 combined with additional services such as:

• Starch and gelatinization assay,
• Analysis of the sugar profile by HPLC,
• Polymer characterization by GPC,
• Infrared spectroscopy (FTIR)

Carrying out analyses at YesWeLab

YesWeLab relies on a network of partner laboratories specializing 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 weights.

The tests are carried out according to good laboratory practices and in compliance with ISO 17025. The protocols can be adapted to the customer's specifications, whether for quality control, R&D study or regulatory validation.

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

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

Technical data

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

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