Soxhlet handle number
The Soxhlet Henkel number (short SHZ , according to the inventors Franz von Soxhlet and Theodor Henkel ), and acid degree of milk , is in especially in central Europe used dimensionless chemical indicator for milk and dairy products . It is given in the unit ° SH (degrees Soxhlet-Henkel).
It is defined as the volume of 0.25 molar sodium hydroxide solution that is required to change the color of the phenolphthalein pH indicator to pink (= alkaline ) in a 100 ml sample :
The SHZ is thus a measure of the titration acidity of milk, which allows statements to be made about its buffer capacity . The SHZ depends on:
- Age of the lactating animals
- the number of lactations
- the length of lactation
- the protein content
- Feeding factors ( carbohydrate , protein, NPN , crude fiber content, nutrient ratio)
so all in all relatively unspecific. Nevertheless, a reduced SHZ can be an indication of subclinical mastitis (insufficient energy supply).
Milk suitable for cheese making must have a Soxhlet Henkel number between 6.0 and 7.4 ° SH.
Other common units for the acidity of milk are the degree Dornic (° D) and the degree Thörner (° Th):
Individual evidence
- ↑ K. Rauscher: Analysis of food: Introduction and instructions for the analysis of food of plant and animal origin including foreign substances and drinking water. VEB Fachbuchverlag 1972, page 415.
- ↑ Wilfried Kraft: Clinical laboratory diagnostics in veterinary medicine. 6th edition, Schattauer Verlag 2005, ISBN 978-3-794-52308-5 , page 456.
- ↑ Gerald Rimbach, Jennifer Möhring, Helmut F. Erbersdobler: Food and goods knowledge for beginners. Springer 2010, ISBN 978-3-642-04485-4 , page 33.
- Titratable acidity. In: milk.polybum.com. Retrieved November 15, 2015 .