SIST ISO 5498:1995 PDF

Agricultural food products -- Determination of crude fibre content -- General method

Title (English):

SIST ISO 5498:1995

Agricultural food products -- Determination of crude fibre content -- General method

Document status:: Active
Format:: Electronic (PDF)
Number of pages:: 8
Publication date:: May 1, 1995
ICS:: 67.050
Technical committee:: KŽP - Agricultural food products

Document language:

enru

Delivery time:1–7 days

Price:123 €

Description (English):

The method consists in boiling with sulphuric acid solution (after any necessary grinding and defatting), and separation and washing of the insoluble residue. Boiling this residue with sodium hydroxide solution, then separation, washing, drying and weighing of the insoluble residue, and determination of the loss in mass on incineration. An annex A specifies methods of extraction of fatty substances. An annex B gives various devices for the separation of crude fibre and supplementary information on the procedures for their use.

Technical details

SKU: SIST ISO 5498:1995

Abstract

Overview

ISO 5498:1981 specifies a general method for the determination of crude fibre content in agricultural food products. Based on the traditional Weende method, the procedure quantifies the fraction of materials that are insoluble and combustible under defined conditions. Results are reported as a percentage by mass, either relative to the product as received or to its dry matter.

Key topics and requirements

Principle: Sequential acid–alkali digestion - boil the sample with a standard sulphuric acid solution, separate and wash the insoluble residue, then boil with a standard sodium hydroxide solution, separate, wash, dry, weigh and determine the loss in mass on incineration (loss on ignition).
Reagents: Specified reagent concentrations (H2SO4 c(1/2 H2SO4) = 0.255 ± 0.005 mol/L ≈ 12.5 g/L; NaOH c = 0.313 ± 0.005 mol/L ≈ 12.5 g/L). Distilled or equivalent purity water and analytical-grade solvents are required.
Sample prep: Grinding (device), sieving (1 mm aperture), and optional preliminary drying. Typical test portion around 3 g (adjustments for special cases noted).
Extraction / defatting: Annex A details options for removal of fatty substances (solvents such as acetone, ethanol, methanol, propan-2-ol, n‑hexane, light petroleum, diethyl ether) and continuous or wash extraction techniques.
Separation devices: Annex B describes a range of separating devices and procedures (filter aids, centrifugation, filtration variants) and guidance on their use.
Operating conditions: Boiling steps conducted at 95–100 °C for 30 ± 1 min each; drying at 130 ± 2 °C; incineration at 550 ± 25 °C to constant mass.
Quality control: At least two determinations per sample; repeatability limits (difference between two results) - absolute 0.4% for crude fibre

Related standards

Mentioned in the description and other SIST standards

Overview

Key topics and requirements

Principle: Sequential acid–alkali digestion - boil the sample with a standard sulphuric acid solution, separate and wash the insoluble residue, then boil with a standard sodium hydroxide solution, separate, wash, dry, weigh and determine the loss in mass on incineration (loss on ignition).
Reagents: Specified reagent concentrations (H2SO4 c(1/2 H2SO4) = 0.255 ± 0.005 mol/L ≈ 12.5 g/L; NaOH c = 0.313 ± 0.005 mol/L ≈ 12.5 g/L). Distilled or equivalent purity water and analytical-grade solvents are required.
Sample prep: Grinding (device), sieving (1 mm aperture), and optional preliminary drying. Typical test portion around 3 g (adjustments for special cases noted).
Extraction / defatting: Annex A details options for removal of fatty substances (solvents such as acetone, ethanol, methanol, propan-2-ol, n‑hexane, light petroleum, diethyl ether) and continuous or wash extraction techniques.
Separation devices: Annex B describes a range of separating devices and procedures (filter aids, centrifugation, filtration variants) and guidance on their use.
Operating conditions: Boiling steps conducted at 95–100 °C for 30 ± 1 min each; drying at 130 ± 2 °C; incineration at 550 ± 25 °C to constant mass.
Quality control: At least two determinations per sample; repeatability limits (difference between two results) - absolute 0.4% for crude fibre

SIST ISO 5498:1995 PDF

Technical details

Abstract

Overview

Key topics and requirements

Related standards

Abstract

Overview

Key topics and requirements

Related standards

Agricultural food products — Determination of crude fibre content — General method

Method to calculate GHG emissions at LNG plant (ISO 6338:2023)

Additive manufacturing of metals - Powder bed fusion (PBF) - In-situ coaxial photodiode monitoring for lack o…

Facility management - Development of the facility management organization (ISO 41002:2026)

Rigid cellular plastics - Determination of compressive properties (ISO 844:2026)

Processing of health care products - Information to be provided by the medical device manufacturer for the pr…

Ophthalmic optics - Uncut finished spectacle lenses - Part 4: Specifications and test methods for the propert…

Anaesthetic and respiratory equipment - Tracheal tubes and connectors - Amendment 1: Reinstatement of third e…