ISO 771-2021 pdf free download – Oilseed meals — Determination of moisture and volatile matter content.
This document specifies a method for the determination of the moisture and volatile matter content ofoilseed meals obtained by the extraction of oil from oilseeds by pressure and/or solvent.
2Normative references
The following documents are referred to in the text in such a way that some or all of their contentconstitutes requirements of this document. For dated references,only the edition cited applies. Forundated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5502,Oilseed residues — Preparation of test samples
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.org/obp
—IEC Electropedia: available at http://www.electropedia.org/
3.1
moisture and volatile matter content
loss in weight measured under the operating conditions specified in this document
Note 1 to entry: The moisture and volatile matter content is expressed as a mass fraction in grams per 100 g.
4Principle
The sample is ground to a particle size of 1 mm, followed by drying of a test portion at (103±Cin anoven at atmospheric pressure, until practically constant mass is reached.
5 Apparatus
5.1Analytical balance, readability 0,000 1 g, weighing precision 0,001 g.
5.2 Mechanical mill, easy to clean and allowing the meals to be ground, without heating and withoutappreciable change in the moisture,volatile matter and oil content, to particles passing completelythrough the sieve (5.3).
5.3Sieve, with apertures of diameter 1 mm.
5.4 Flat-bottomed vessel, of metal, resistant to attack under the test conditions, provided with a well-fitting lid and allowing the test portion to be spread to about 0,2 g/cm2 (e.g. diameter of vessel 50 mmto 70 mm, height about 30 mm).Glass vessels with ground closures may also be used.
5.5 Electric oven, with thermostatic control and good natural ventilation, capable of being regulatedso that the temperature of the air and of the shelves in the neighbourhood of the test portions liesbetween 101 C and 105 C in normal operation.
5.6 Desiccator，containing an efficient desiccant and provided with a metal plate that allowsvessels (5.4) to cool rapidly.
6 sample
6.1 Sampling
Sampling is not part of the method specified in this document. A recommended sampling method isgiven in ISO 5500.A representative sample should have been sent to the laboratory. It should not havebeen damaged or changed during transport or storage.
6.2 Preparation of test sample
Prepare the test sample in accordance with ISO 5502. Grind the contract sample in the previously well-cleaned mechanical mill (5.2), collect the grindings, mix carefully and carry out the analysis without delay.
7Procedure
7.1Carry out two determinations on each sample.
7.2 Weigh the vessel to the nearest 0,001 g with the lid (5.4), after leaving it open for at least 30 min inthe desiccator (5.6) at laboratory temperature. Note mass mo-
7.3 Weigh, to the nearest 0,001 g, about 5 g of the test sample into the vessel (5.4), spread the sampleuniformly over the whole base of the vessel, and re-weigh with its lid.Carry out these operations asquickly as possible, in order to avoid any appreciable change in moisture content. Note mass m;.
7.4 Place the vessel with the test portion in the oven (5.5), which has previously been set to atemperature of (103± 2)C, and take off the lid.
lf several vessels are in the oven together, arrange them in such a way that air can circulate freelybetween them.ISO 771 pdf download.