Phenolic assay

The measurement of phenolic compounds allows for the assessment of the natural antioxidant content present in a wide variety of plant, food, nutraceutical, and cosmetic matrices. These compounds play a vital role in protecting against oxidative stress, ensuring product stability, and preventing lipid rancidity. Their quantification is therefore a key indicator of product quality, freshness, and functional properties.

Principles and analytical methods

Two analytical approaches are commonly used for the determination of total phenols:

• Spectrophotometry (Folin-Ciocalteu method) : This method relies on the reduction of Folin's reagent by phenolic compounds, resulting in the formation of a colored complex that is measured at a specific wavelength. This overall method allows for the estimation of the total polyphenol content, expressed as gallic acid equivalents.
• High-performance liquid chromatography (HPLC) : This technique allows for the identification and quantification of each phenolic molecule individually, such as gallic acid , catechin , quercetin , rutin , or caffeine . It offers superior resolution and precision, suitable for the detailed characterization of plant extracts and complex formulations.

To delve deeper, also discover the assay of quercetin , the assay of catechin or the assay of gallic acid , available in our catalogue.

Industrial applications

Phenolic analysis is used in many sectors:

• Agri-food : control of the oxidative stability of oils, wines, juices, teas or plant extracts rich in polyphenols.
• Nutraceuticals and food supplements : evaluation of the antioxidant potential of natural ingredients and validation of health claims.
• Animal nutrition : analysis of plant raw materials (plants, fodder, extracts) to characterize their functional value.
• Natural cosmetics and skincare : determination of the phenols responsible for the anti-aging and protective properties of the formulas.
• Active materials and packaging : measurement of added antioxidants to limit oxidation and extend product shelf life.

Analytical interest and complementarity

This assay is often combined with other analyses to characterize the complete antioxidant profile of a sample. It can be coupled with:

• an analysis of total antioxidant capacity (ORAC, DPPH, ABTS) ;
• an analysis of total flavonoids ;
• or even a dosage of condensed tannins for a more specific approach.

Combining these tests allows for a complete evaluation of the bioactive potential of natural extracts and better control of the quality of industrial formulations.

YesWeLab Services

At YesWeLab, we select partner laboratories based on your analytical needs, the matrices to be analyzed, and the desired methods (spectrophotometry, HPLC, GC-MS, etc.). Our partners are ISO 17025 accredited and/or COFRAC recognized to guarantee the reliability of the results.
Thanks to our digital platform , you can centralize your analysis requests, track your samples, and receive your results online.

Since 2020, many manufacturers, distributors and design offices have trusted us for their innovation and quality control projects.

To obtain a quote or further information about this test, please contact our scientific team .