The standard "EN ISO 13906 Animal feeds - Determination of acid detergent fiber (ADF) and acid detergent lignin (ADL) contents", which is based on a European standard and later published by the International Organization for Standardization (ISO), describes a method for the determination of insoluble residue of acid detergent fiber (ADF) and acid detergent lignin (ADL) in all types of animal feed. The limit of determination is 1 mass fraction of acid detergent fiber and 1,5 mass fraction of acid detergent lignin. Gravimetric routine and reference methods are used.
For the purposes of this standard, the following terms and definitions apply:
In the first stage of the method, the acid detergent fiber content is determined. Cationic detergent solution is used to remove acid-labile carbohydrates, protein that is not converted to Maillard products (heat damaged), and fats. The remaining fibrous residue is primarily cellulose and lignin (vegetable products) or insoluble protein complexes (animal products and heat damaged feeds). The residue is weighed to determine the acid detergent fiber content. In the second stage, the remaining residue is dissolved with 72 mass percent (12,00 mol/l) sulfuric acid, leaving the acid detergent lignin content, which is determined gravimetrically.
As reagents, only reagents of recognised analytical grade and only distilled or deionised water or water of at least equivalent purity are used unless otherwise stated.
A representative sample must be sent to the laboratory. The sample must not have been damaged or altered during transport or storage. Sampling is not part of the method specified in this standard. A recommended sampling method is included in ISO 6497.
The test sample is prepared in accordance with ISO 6498. The laboratory sample is reduced to approximately 100 g (dry weight equivalent) and half of it is placed in a moisture-proof, closed container for the determination of total moisture. The remaining wet (minimum 15 percent mass fraction moisture) materials are dried in a ventilated oven at no more than 60 degrees to a maximum of 15 percent mass fraction moisture. Drying at no more than 60 degrees is necessary to prevent the formation of artificial fibers and lignin. Dry test samples are ground using a mill. Grinding separates the materials with the most fibrous material passing through the sieve last. The material in the mill is not discarded but instead added to the ground test sample.
Preextraction is required for test samples containing at least 10 mass percent oil and is recommended for test samples containing at least 5 mass percent oil. Test samples are weighed into prescreened, oven-dried crucibles, placed in a crucible filtration manifold, extracted four times with 30 ml to 40 ml of acetone, allowing the material to soak in acetone for 3 to 5 minutes each time, vacuumed to remove all traces of acetone, air dried for 10 to 15 minutes, and the residue transferred to a reflux vessel for fiber analysis. The same crucible is used to collect fiber residue for each test portion after acid detergent extraction.
For the Fibertec type apparatus, the crucible is placed in a cold extraction unit and filled with 25 ml of acetone. It is left for 3 to 5 minutes and filtered by applying vacuum. This process is repeated three times.
Our organization, which has been trying to support businesses from every sector with its testing, measurement, analysis and evaluation studies carried out in a wide range for years, has a strong staff that closely follows the developments in the world in the field of science and technology and constantly improves itself. In this context, testing services in accordance with the standard "EN ISO 13906 Animal feeds - Determination of acid detergent fiber (ADF) and acid detergent lignin (ADL) contents" are also provided to businesses.
To get an appointment, to get more detailed information or to request an evaluation, you can ask us to fill in our form and reach you.
