Determination of insoluble, soluble, and total fiber (gravimetric method)

Dietary fiber analysis is essential for characterizing the nutritional quality of a product, validating regulatory labeling, or supporting a health claim. At YesWeLab, we perform soluble, insoluble, and total fiber analysis using gravimetric methods, a reference technique recognized for its reliability and reproducibility across a wide range of matrices: dry extracts, food powders, and flours.

Principle of the gravimetric method

The gravimetric method relies on the selective removal of digestible compounds from the sample, followed by weighing the remaining fibrous residue. Specifically, the sample undergoes a series of enzymatic treatments (amylase, protease, amyloglucosidase) that hydrolyze the starch and proteins. The fibers, undigested by these enzymes, are then isolated, filtered, dried, and weighed. A correction is applied to account for residual proteins and ash.

This approach allows us to distinguish:

• insoluble fibers (cellulose, hemicelluloses, lignin), which precipitate after processing;
• soluble fibers (pectins, gums, beta-glucans, inulin partially), recovered after precipitation with ethanol;
• total fiber, sum of the two fractions.

The result, expressed in g/100 g, offers a simple and reliable assessment of the fibre content, directly usable for the nutritional declaration in accordance with the INCO regulation (EU No. 1169/2011).

Soluble, insoluble, total fiber: what are the differences?

Soluble fibers form a gel upon contact with water and play a role in blood sugar and cholesterol levels; insoluble fibers promote intestinal transit. Understanding the ratio between these two fractions is essential for manufacturers in the nutraceutical, human food, and herbal supplement sectors who wish to highlight a specific fiber profile or substantiate a health claim.

Matrices analyzed

The gravimetric method is particularly well-suited to dry extracts, food powders, flours, dehydrated preparations, and plant powders. If your matrix has any specific characteristics (high sugar content, presence of polyols, novel food fibers), please specify this in your request: our scientific team will adapt the protocol accordingly.

Further analyses of the catalogue

Fiber analysis is often part of a more comprehensive nutritional profile. We recommend combining this analysis with other services from our analysis catalog :

• Another fiber approach by fractionation: the dosage of NDF, ADF, ADL fibers (Van Soest method), ideal for forages and animal feed;
• Starch measurement , complementary to complete the carbohydrate balance;
• Analysisof polysaccharides to precisely identify carbohydrate fractions;
• The dosage of dry matter, essential to express the results on a dry basis;
• The determination of the chemical composition for an overall profile (proteins, lipids, ash, moisture);
• Glyceride composition and vitamin analysis to complete the nutritional value;
• Bioavailability measurement to assess nutrient assimilation.

Find all our services on the laboratory nutritional analysis.

Why entrust your fiber dosage to YesWeLab?

At YesWeLab, we collaborate with a rigorously selected network of laboratories, most of which are certified and/or accredited (ISO 17025, COFRAC, etc.). These laboratories are chosen based on your specific needs, the matrices to be analyzed, and the required analytical techniques or methods.

If you have specific requirements, please don't hesitate to mention them in your request: our scientific team will do everything possible to respond accurately and promptly. Since 2020, numerous manufacturers, distributors, and engineering firms have entrusted us with the management of their analyses, sending us their samples via our digital platform.

Request a quote for a dietary fiber analysis

Do you want to know the soluble, insoluble, and total fiber content of your product? Add this analysis to your quote in just a few clicks or contact our scientific team for personalized support. We guarantee fast processing, a choice of laboratory suited to your product matrix, and actionable results for your labeling and claims.