ISO 6571:2008 pdf free.Spices, condiments and herbs — Determination of volatile oil content (hydrodistillation method).
1 Scope
ISO 6571 specifies a method for the determination of the volatile oil content of spices,condiments and herbs.
2 Normative references
The following referenced documents are indispensable for the application 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 939, Spices and condiments — Determination of moisture content — Entrainment method.
ISO 2825, Spices and condiments — Preparation of a ground sample for analysis.
4 Principle
An aqueous suspension of the product is distilled. The distillate is collected in a graduated tube containing a measured volume of xylene to fix the volatile oil. The organic and aqueous phases are then allowed to separate and the total volume of the organic phase read. The volatile oil content is calculated after deducting the volume of xylene.
6 Apparatus
Usual laboratory equipment, and in particular the following.
6.1 Distillation apparatus, made of strong glass having a low coefficient of thermal expansion1).
The apparatus comprises the following components connected by ground glass joints.
6.1.1 Round-bottom flask, viith a ground neck, of capacity 500 ml or 1 000 ml, according to the product concerned (see Annex A).
6.1.2 Condenser system, comprising the following components joined together (see Figure 1):
a) a vertical tube (AC), the base of which has a ground joint to fit the flask (6.1.1);
b) a bent tube (CDE);
c) a vertical bulb condenser (FG);
d) an assembly consisting of a tube with a side-arm (K) provided with a ground stopper (K’), a pear-shaped enlargement (J), a tube graduated in divisions of 0,05 ml (JL), a spherical enlargement (L) and a threeway tap (M) connected to the vertical tube (AC) by an inclined tube (0) pro’vided with a safety tube (N), if necessary topped by the steam trap (6.1.3).
7 Sampling
A representative sample should have been sent to the laboratory. It should not have been damaged or changed during transport or storage.
Sampling is not part of the method specified in this International Standard. A recommended sampling method is given in ISO 948.
8 Procedure
MOTE It is intended to specify the test parameters in the International Standard specifying requirements for each spice or condiment. In the meantime, these parameters are given in Annex A.
8.1 Preparation of the apparatus
Carefully clean the condenser system (6.1.2). Tightly fix the glass stopper (K) on the side-arm (K) and the steam trap (6.1.3) on the safety tube (N). Turn the apparatus upside down, fill it with the cleaning solution (5.2) and leave it in this position overnight. Rinse the apparatus very carefully with water after having cleaned it.
8.2 Preparation of the test sample
If the test portion has to be ground (see Annex A), crush a sufficient quantity of the laboratory sample just before adding to the round-bottom flask to a suitable degree of fineness according to the product concerned (see ISO 2825). During the crushing procedure, ensure that the temperature of the test portion does not rise.ISO 6571:2008 pdf free download.