Process Design - J.P. SELECTA 4002841 Manual De Instrucciones

MANUAL DE INSTRUCCIONES CODIGO 80196 REV B
J
.P. SELECTA s.a.u.
Octubre 2019

12 Process design

The analysis process can vary depending on the nature of the sample. Before a
process can be established, it is necessary to carry out a series of tests of known
fat determinations. Once the process is designed, it is advisable to validate it with
inter-laboratory exercises.
The following steps show the general process for the determination of fats:
1. Representative sampling of the samples
2. Homogenize, grind, grind ... the sample
3. Weigh the samples and tarnish the glasses. Number them.
4. Drying of the samples
5. Hydrolysis (optional)
6. Extraction
7. Solvent evaporation
8. Weigh and calculate the fat% on the sample weight
A first guidance on the process to follow can be obtained from the official tests or
trials already designed. Although these are designed using the classic soxhlet method
they are easily modifiable to execute them with the DET-GRAS extraction equipment.
Initially, respect the operations described in the test outside the extraction.
Homogenization and grinding must be carried out without losing fat during handling.
For this, it is advisable to prepare a large sample quantity (Ex: 1Kg) so that the effect
of fat loss is negligible.
Another technique is to crush the sample in a container that can be completely cleaned
with a solvent impregnated cotton so that the lost fat in the walls of the container
is part of the sample.
In general, in the extraction, the "Rinsing" phase must be longer than "Boiling",
since it is the proper stage of extraction. The "Boiling" phase can be understood as
"preparation" to facilitate extraction.
Normally the meat tests recommend a hydrolysis prior to extraction. Hydrolysis com-
plicates the test so you can study the steps of crushing, drying, extraction to avoid it.
Hydrolysis consists in the removal of organic matter by boiling the sample in HCl from
3 to 5N. Subsequently, each sample is washed by filtration. In the filter paper, after
several washes, only fat remains. The paper is inserted into the extraction cartridge
and then inserted into the extractor. Since fat is manifestly exposed to the action of
the solvent extraction is very fast and complete.
Hydrolysis can be carried out with usual laboratory material such as heating plates,
Erlenmeyer jars, filtration funnels, filter paper, ...
Choosing the solvent and the extraction temperature:
Check in standards, specialized books, etc. which is the appropriate solvent for the
extraction that is wanted to carry out. In case you do not have any information, oil
ether is used 60-80ºC.
It should also be taken into account that the working temperature does not spoil the
extracted grease.
Normally, use the extractor's own temperatures for each solvent.
Autovía A2 Km 585.1 Abrera 08630 (Barcelona) España
e-mail: selecta @jpselecta.es - website: http://www.jpselecta.es
(Sujetas a modificaciones sin previo aviso)
Tel 34 937 700 877 Fax 34 937 702 362
Pag.: 42