3 | Product description
BÜCHI Labortechnik AG
10/30
Operation Manual HydrolEx H-506
3
Product description
3.1
Description of function
The hydrolysis frees fatty substances which are mechanically surrounded by different
constituents (carbohydrates and protein in undamaged cells or starch membranes).
This is also true for colloid-disperse fractions (protein) which, as a result of surface
forces, coat the fat drops (milk, cream, cheese) and for certain fat fractions which are
bound, chemically or adsorptively to other components (phosphatide-protein com-
plexes in yeast, eggs, etc.).
For fat determination including acid hydrolysis such as the method according to
Weibull-Stoldt in food and animal feed, the product is to be hydrolyzed to make the fat
accessible for extraction. Thus a reproducible fat determination is possible.
3.1.1
Principle of hydrolysis
1. The sample is boiled in hydrochloric acid to break down proteins and high-molec-
ular carbohydrates into acid-soluble constituents.
2. The sample is filtered over a layer of Celite® and sand in a glass sample tube and
dried. The free fat in the hydrolysate adsorbs on the Celite® in the glass sample
tube. The underlying sand layer prevents the Celite® from reaching the frit of the
glass sample tube.
3. The fat can be extracted with an appropriate solvent.
