BS ISO 939:2021 pdf download – Spices and condiments — Determination of moisture content
This document specifies an entrainment method for the determination of the moisture content of spices and condiments.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 948, Spices and condiments — Sampling
ISO 2825, Spices and condiments — Preparation of a ground sample for analysis
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
moisture content
content of water extracted or collected in accordance with the method prescribed in this document Note 1 to entry: Moisture content is expressed as a percentage by mass.
4 Principle
Determination of the amount of water entrained by azeotropic distillation, using an organic solvent immiscible with water, and collected in a graduated tube.
5 Reagents
5.1 Toluene.
Saturate the toluene by shaking with a small quantity of water and distil. Use the distillate for the determination of the moisture.
NOTE Different solvents are used for the determination of moisture.
Unless otherwise specified in the International Standard giving specifications for the spice or condiment in question, toluene shall be the solvent used for the determination.
9 Expression of results
The moisture content (w), in percentage by mass, can be expressed by Formula (1):
where
V is the volume of water collected, in ml;
m is the mass of the test portion, in g.
It is assumed that the density of water is 1 g/ml exactly.
10 Test report
The test report shall show the method used and the result obtained. It shall also mention all operating conditions not specified in this document, or regarded as optional, as well as any circumstances that may have influenced the result.
The report shall include all details required for complete identification of the sample.BS ISO 939 pdf download.