BS ISO 03632-2:2010 pdf free download – Spices一Saffron (Crocus sativus L.) Part 2: Test methods.
10.2 Saffron in filaments and cut filaments
Crush the test sample (see Table 1) using the cwsher (10.1.1) until 95 % mass fraction of the powder passes through the sieve (10.1.2).
Then, reincorporate the material remaining on the sieve and homogenize the whole.
10.3 Saffron in powder form
Sieve the test sample (see Table 2) using the sieve (10.1.2) in order to verify that 95 % mass fraction of the powder passes through it.
If this is not the case, crush the powder in the crusher (10.1.1)to obtain the required particle size. Then, reincorporate the material remaining on the sieve and homogenize the whole.
11 Determination of extract soluble in cold water
Proceed in accordance with the method given in ISO 941.
For saffron in filaments, cut filaments and in powder forms, take a test portion of 2,00 g ± 0,01 g.
12 Determination of total ash
Proceed in accordance with the method given in ISO 928.
For saffron in filaments, cut filaments and in powder forms, use the sample which was used for the determination of the moisture content (7.4.2).
13 Determination of acid-insoluble ash
Proceed in accordance with the method given in ISO 930.
For saffron in filaments, cut filaments and in powder forms, use the sample which was used for the determination of the total ash (Clause 12).
14 Determination of the main characteristics using a UV-vis spectrometric method
14.1 General
This method enables the determination of the main characteristics of saffron connected with picrocrocin, safranal and crocin content. It is directly applicable to saffron in powder form provided that the powder conforms to the requirements of 10.3 and to saffron filaments and cut filaments after crushing and sieving in accordance with 10.2.
14.2 Principle
Measurement of the variation in optical density between 200 nm and 700 nm of an aqueous extract of saffron at ambient temperature.
14.3 Apparatus
Usual laboratory equipment and in particular the following.
14.3.1 Spectrometer, suitable for recording optical density in the ultraviolet-visible (UV-vis) band between
200 nm and 700 nm.
14.3.2 Quartz cell, with an optical pathlength of 1 cm.
14.3.3 One-mark volumetric flasks, capacity 200 ml and 1 000 ml, ISO 1042[] class A, in anti-actinic glass.
14.3.4 One-mark pipette, capacity 20 ml, ISO 648[2] class A.
14.3.5 Filtration membrane, made of cellulose acetate or made of hydrophilic polytetrafluoroethylene (PTFE) [Millex-LCR1)] of porosity 0,45 pm.
14.4 Procedure
14.4.1 Test portion
Weigh, to the nearest milligram, 500 mg of the sample (see Table 1 or Table 2) in a shoe glass.
14.4.2 Determination
Transfer quantitatively the test portion into a 1 000 ml one-mark volumetric flask (14.3.3). Add about 900 ml distilled water (analytical grade).
Stir with a magnetic stirrer (1 000 r/min) for 1 h, away from light. Remove the magnetic bar. Make up to the mark with distilled water. Close with a glass stopper and homogenize.
Take an aliquot part with the 20 ml pipette (14.3.4). Transfer into a 200 ml one-mark volumetric flask. Make up to the mark with distilled water. Close with a glass stopper and homogenize.
Filter the solution, rapidly and away from light, through the membrane (14.3.5) so as to obtain a clear solution.
Adjust the spectrometer (14.3.1) and record the variation in absorbance of the filtered solution between 200 nm and 700 nm using distilled water as the reference liquid. An example of a UV-vis profile is given in Annex C.