Filter Bag Fiber Analyzer

What is the Filter Bag Fiber Analyzer?

A filter bag fiber analyzer places samples in porous bags and digests, rinses and extracts them in a shared vessel, allowing many samples per batch. It is a rapid format for NDF, ADF and crude fiber in feed and forage testing.

Overview

Samples are weighed into filter bags of defined porosity, sealed and loaded into a rotating or reciprocating vessel that holds up to 24 bags. Detergent solution circulates through the bags under heat, and after digestion the solution is drained and the bags are rinsed and dried in a batch. Because all bags share the same solvent bath, reagent use per sample is low and the process is easy to automate. However, the method requires careful sealing and bag handling, and a blank bag is included to correct for any bag mass change. After drying, bags can be ashed in a muffle furnace or used for sequential analysis, and the residue is calculated as a percentage of the sample mass. Results correlate well with conventional crucible methods when validated.

How does it work?

Fiber is a family of carbohydrate polymers and lignin that resist digestion, so methods measure an operationally defined residue. The Weende crude fiber method digests the sample sequentially with dilute acid and alkali, then filters, dries, ignites and weighs the residue, capturing cellulose and part of the lignin. Detergent methods use neutral or acid detergent solutions to isolate neutral detergent fiber, which includes hemicellulose, cellulose and lignin, or acid detergent fiber, which excludes hemicellulose. Enzymatic-gravimetric dietary fiber methods treat the sample with amylase, protease and amyloglucosidase to remove starch and protein, then precipitate soluble fiber with alcohol and weigh the total residue, correcting for ash and protein. HPLC-based methods quantify individual fiber fractions after enzymatic digestion, which supports labelling of specific fiber types.

What are the key features?

• Batch capacity up to 24 filter bags
• Shared solvent bath for low reagent use
• Sequential NDF, ADF and lignin procedures supported
• Automatic agitation, drainage and rinse cycles
• Blank bag correction for bag mass change
• Short digestion times from 60 minutes

What are the technical specifications?

A typical filter bag fiber analyzer configuration offers batch capacity of Up to 24 filter bags, bag porosity of 25 µm nominal, digestion time of 60–75 min per stage, temperature of Up to 100 °C, controlled, procedures of NDF, aNDF, ADF, ADL, crude fiber and sample mass of 0.3–1 g. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Filter Bag Fiber Analyzer is used in rapid NDF and ADF for feed and forage, crude fiber testing in feed mills, sequential lignin determination and contract laboratory fiber throughput. Across the wider Fiber Analyzers class, laboratories also deploy it for dietary fiber declaration for nutrition labelling, crude fiber compliance for feed and export and NDF and ADF values for ration formulation.

Which standards and certifications apply?

Relevant standards and methods include ISO 5498, ISO 6541, ISO 6865, ISO 16472, AOAC 991.43, AOAC 985.29, AOAC 2011.25 and ISO/IEC 17025. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Fiber analysis is sensitive to filtration and transfer losses, so crucibles, fritted glassware and filter bags must be prepared, dried and weighed consistently, and residues must be handled without spillage. Enzyme activities vary between lots, so incubation times, temperatures and pH buffers must follow the method exactly, and each batch should include a blank and a control sample. The ashing step requires a muffle furnace at 525 to 550 °C with a stable, calibrated controller. Drying and cooling to constant mass before weighing are essential for gravimetric accuracy. Because results are operationally defined, laboratories should state the method, the corrections applied and participate in proficiency-testing schemes for dietary fiber.

How do I select the right Filter Bag Fiber Analyzer?

Select a filter bag system when throughput and reagent economy matter and your methods allow the bag format. Confirm that bag porosity suits your sample particle size and that sequential NDF, ADF and lignin procedures are supported. Validate results against the crucible method for representative samples.

How does it compare with other Fiber Analyzers variants?

Choose the method according to the fiber value you must report. Crude fiber is an older, inexpensive measure still used for feed regulation and some export certificates, but it underestimates total fiber considerably. Detergent fiber methods give NDF and ADF values used in feed formulation and ruminant nutrition, and they are rapid with filter bag systems. For human nutrition labelling, enzymatic-gravimetric methods such as AOAC 991.43 give total dietary fiber and, with additional steps, insoluble and soluble fractions. HPLC-based methods are needed when individual fiber components, such as beta-glucan or inulin, must be declared or studied. Always check that the accredited method applies to your matrix and that ash and protein corrections are included.