Global standard for detergent fiber analysis of animal feed with Fibertec as suitable option
A new standard for determination of acid detergent fiber (ADF) and acid detergent lignin (ADL) content has been approved by CEN and ISO.
The new standard is entitled ‘EN ISO 13906:2007 Animal feeding stuffs – Determination of acid detergent fibre (ADF) and acid detergent lignin (ADL) contents. It describes the use of refluxing apparatus and gives the FOSS Fibertec system as a suitable option. Fibertec was used by 18 of the 22 laboratories taking part in the collaborative study.
FOSS product manager for Fibertec, Maria Wiberg Wickman said: “Finally, we have a worldwide standard for ADF and ADL. By using an officially approved method you will get results that are valid on a worldwide basis.”
An approved standard for Neutral Detergent Fiber (NDF) already exists, ISO/FDIS 16472:2005. This also states the Fibertec system as a valid option.
Fibertec system a suitable option
The advantage of Fibertec apparatus compared to the manual (refluxing in beakers) can be summed up as follows:
- No transfer of sample improves accuracy and precision. The sample is weighed into the crucible and kept there throughout the analysis
- Integrated system for extraction and filtration of 6 samples at a time
- Quick vacuum filtration with anti-clog system
- Minimum contact with reagents as the system offers both heating up and addition of reagents and water
- Reagent addition system also offers simple wash down of sample stuck to the walls
- The built-in timer ensures that extraction conditions are kept from batch to batch
- Cold Extraction Unit for the ADL step
Detergent fiber analysis background
The concept behind the detergent fiber analysis is that plant cells can be divided into less digestible cell walls (comprising hemicellulose, cellulose and lignin) and mostly digestible cell contents (comprising starch and sugars). These two components can be separated by use of two detergents: a neutral detergent and an acid detergent.
Fibre in feeds is a nutritionally defined entity. It represents the indigestible and slowly digested fractions in feed. Acid detergent solution (ADS) dissolves the acid-labile carbohydrates, fats and protein that are not complexed in Maillard products (heat-damaged). This leaves a fibrous residue that is primarily cellulose and lignin (plant products) or insoluble protein complexes (animal products and heat-damaged feeds). Acid detergent lignin is defined as the residue remaining after cellulose and other organic matter in ADF is solubilized by 72 % H2SO4.
More information
A description of the EN ISO 13906:2007method can be ordered via the ISO web site.
