Determination of condensed (proanthocyanidin) and hydrolyzable tannins

The analysis of condensed tannins (proanthocyanidins) and hydrolyzable tannins is essential for the physicochemical and nutritional characterization of plant matrices. These phenolic compounds play a major role in the organoleptic, functional, and biological properties of many plant-derived products. Their precise quantification is indispensable in quality control, research and development, raw material selection, and regulatory compliance, particularly in the human food and nutraceutical sectors.

This analysis allows simultaneous measurement of the two major families of tannins present in the same matrix, offering a complete and consistent view of the phenolic composition of the analyzed product.

Principle of analysis

Tannins are complex polyphenols capable of interacting with proteins, polysaccharides, and other constituents of plant matrices. They are divided into two main categories with distinct properties and analytical behaviors.

Condensed tannins, also called proanthocyanidins, are composed of flavanol polymers. They are widely found in fruits, barks, seeds, tea, and certain medicinal plants.
Hydrolyzable tannins are formed from phenolic units esterified to a carbohydrate core, generally released by acid hydrolysis.

The analysis relies on a suitable preparation of the sample, including extraction steps and, if necessary, acid hydrolysis to allow reliable and reproducible quantification of each tannin family.

Analytical methods used

Depending on the nature of the matrix and the analytical objectives, different approaches can be implemented.

High-performance liquid chromatography (HPLC) allows for the fine separation of phenolic compounds and the precise quantification of tannins, particularly when detailed profiles or improved analytical specificity are required.
Spectrophotometry is used for overall or comparative analyses, especially after hydrolysis, and is a robust and widely used method for assessing total tannin content.

The choice of technique is defined upstream by the YesWeLab scientific team in order to ensure the relevance of the results with regard to the matrices analyzed and the industrial or regulatory objectives.

Measured parameters

This analysis allows, in particular, the determination of the condensed tannin (proanthocyanidin) content, the hydrolyzable tannin content, the relative distribution between these two families, and the comparison between batches, suppliers, or formulations.
The analytical results provide an objective basis for quality assessment, raw material standardization, and monitoring of processing methods.

Matrices involved

Tannin analysis is applicable to a wide variety of plant matrices, including plant extracts, plant powders, botanical raw materials, fruits, barks, tea, and certain nutraceutical ingredients.
Each matrix undergoes specific preparation to minimize interference and ensure reliable quantification of the tannins present.

Industrial applications

This analysis is widely used in various industrial contexts. It is involved in the quality control of plant raw materials, the selection and qualification of suppliers, the development and standardization of plant extracts, as well as monitoring the consistency of composition over time.

In the human food and nutraceutical sectors, tannin analysis is also used for evaluating functional properties, controlling sensory characteristics such as astringency, and for the nutritional characterization of products.

Finally, it is used in investigative procedures in cases of non-compliance, profile variation, or problems related to product stability.

Sectors concerned

This service is primarily aimed at stakeholders in the human food, nutraceutical, and plant and plant-based ingredient sectors. It also concerns manufacturers involved in the formulation of products based on plant extracts or botanical raw materials.

Regulatory issues and quality

Analytical characterization of tannins helps to ensure the accuracy of technical documentation, composition declarations, and traceability requirements associated with plant products. Reliable analysis allows for proactive inspections, reduces the risk of non-compliance, and guarantees consistent product quality on the market.

In a context of increasing demands for transparency and standardization, tannin analysis constitutes a strategic analytical tool.

Other analyses from the YesWeLab catalogue

• The analysis of total polyphenols makes it possible to assess the overall content of phenolic compounds and to place tannins in a broader context of antioxidant composition of plant raw materials.
• Flavonoid analysis is a relevant analytical complement, particularly for matrices rich in flavanols and bioactive phenolic compounds, often associated with condensed tannins.
• proanthocyanidin analysis allows for finer characterization of condensed tannins, particularly when standardization or batch-to-batch comparison requirements are necessary.
• HPLC chromatographic analyses are used for the separation and quantification of many phenolic compounds, whether tannins, flavonoids or other polyphenols present in complex plant matrices.
• LC-MS analyses offer increased sensitivity and are suitable for advanced characterization needs, including the identification of specific compounds or the management of strongly interfering matrices.
• Finally, the nutritional analyses offered by YesWeLab make it possible to integrate the dosage of tannins into a complete approach to the composition of products, including other nutritional and functional parameters.

YesWeLab Expertise

YesWeLab relies on a rigorously selected network of partner laboratories, most of which are certified or accredited according to recognized standards such as ISO 17025 and COFRAC. Each request is analyzed by our scientific team to direct samples to the analytical method best suited to the project objectives and the specific constraints of the matrices.

Thanks to its digital platform, YesWeLab enables centralized analysis management, optimized sample tracking, and fast, secure access to analytical results. Since 2020, numerous manufacturers, distributors, and research firms have trusted YesWeLab for their physicochemical and nutritional analyses.

For any quote request or to discuss your specific needs in dosing condensed and hydrolyzable tannins, contact the YesWeLab team now.