ISO 6541:1981

Name: ISO 6541:1981 — Agricultural food products — Determination of crude fibre content — Modified Scharrer method
SKU: ISO 6541:1981
Price: 25 EUR
Availability: InStock

Agricultural food products — Determination of crude fibre content — Modified Scharrer method

Название (английский):

ISO 6541:1981

Agricultural food products — Determination of crude fibre content — Modified Scharrer method

Статус документа:: Действующий
Формат:: Электронный (PDF)
Количество страниц:: 4
Дата публикации:: 1 июня 1981 г.
Издание:: ISO IS 6541 edition 1 version 1
ICS:: 67.050

Тип поставки:

Full version25 €Ask AI2 €Read online 24h10 €Read online 72h15 €

Язык документа:

ruen

Срок поставки:1 рабочий день

Цена:25 €

Описание (английский):

The method is applicable to cereals and cereal products as well as to certain products containing less the 1 % of crude fibre. It consists in boiling with a mixture of acetic acid, nitric acid and trichloroacetic acid (after any necessary grinding and defatting). Then separation and washing of the insoluble residue on a filter crucible. Drying and weighing of the insoluble residue, and determination of the loss of mass on incineration.

Abstract

Похожие стандарты

Стандарты, упомянутые в описании

Overview

ISO 6541:1981 specifies a conventional laboratory method - the Modified Scharrer method - for the determination of crude fibre content in agricultural food products. It is intended primarily for cereals and cereal products and for certain low–fibre materials (including some yeasts and products with <1% crude fibre). The method measures the fraction of material that is insoluble under specified acid digestion and combustible on incineration, and expresses results as a percentage by mass (either relative to the product as received or to dry matter).

Key topics and technical requirements

Principle: Boiling the defatted/ground sample with the Scharrer reagent (a mixture of acetic acid, concentrated nitric acid and trichloroacetic acid), collecting and washing the insoluble residue, drying, weighing, and determining loss on ignition by incineration.

Reagents & materials: Scharrer reagent (composition defined in the standard), acetone, diethyl ether, sea sand, crushed porcelain, and analytical-grade solvents.

Sample preparation:

Grind samples so that at least 95% pass a 1 mm sieve when required.
Typical test portion sizes: 1–3 g (for ~5% crude fibre); use ~3 g for low-fibre products (<1%).
Defatting may be required for fatty samples (refer to ISO 5498 for defatting methods).

Apparatus & conditions:

Reflux digestion vessel and condenser; glass rod; silica fritted filter crucible (porosity grade P100, 40–100 µm).
Boil with Scharrer reagent for 30 ± 1 minutes without stirring; control foaming.
Dry residue at 130 ± 2 °C, cool in desiccator and weigh to 0.5 mg repeatability.
Incinerate residue at 550 ± 25 °C (typically 30 min) and reweigh to determine loss on ignition.

Calculations & quality control:

Crude fibre calculated as percentage by mass relative to sample or dry matter; formulas and correction factors are given in the standard.
At least two determinations per sample; repeatability limits and reporting requirements are specified.

Applications and who uses this standard

Food testing laboratories performing routine proximate analysis for cereals and cereal products.

Cereal mills, grain processors and bakeries for quality control and ingredient specification.

Feed and nutrition analysts assessing fibre fractions relevant to animal diets.

Regulatory agencies and labeling authorities where crude fibre values are required.

Academic and industrial research into cereal composition and processing effects.

ISO 6541 provides a reproducible, internationally recognized procedure for crude fibre determination where the Modified Scharrer method is appropriate.

Related standards

ISO 5498 - Determination of crude fibre (general method) and defatting procedures

ISO 3310/1 - Test sieves - Technical requirements (sieve apertures)

ICC Standard No. 113 - Basis for this ISO method (International Association for Cereal Chemistry)

IUPAC endorsement noted in the standard

Keywords: ISO 6541, crude fibre determination, Modified Scharrer method, cereals, cereal products, food analysis, crude fiber content, laboratory method.

ISO 6541:1981

Abstract

Похожие стандарты

Overview

Key topics and technical requirements

Applications and who uses this standard

Related standards

Технические детали

ISO 5498:1981

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

ISO 654:1980

Short solid-stem thermometers for precision use

BS ISO 3310-1:2016

Test sieves. Technical requirements and testing. Test sieves of metal wire cloth.