Velp Scientifica
– UDK139 Operating Manual
10004762/B5
83
13 - Kjeldahl method to determine the protein content on bacon,
ham, hot dog, salami, sausage
Procedure
1) Sample:
2g of sample weighed with an accuracy of
0.1mg after homogenizing.
2) Reagents for digestion:
for every sample add in the test tube:
2 catalyst tablets CM (code CT0006650)
15 ml sulphuric acid concentrated (H
2
SO
4
)
shake gently the test tube with the sample.
3) Digestion:
heat for 75 min at 420 °C.
4) Cooling:
let cool the test tubes to 50-60 °C.
5) Distillation-titration:
place in position the test tube with digested sample in the
unit UDK 139.
factor: 6.25
Addition of reagents:
dilution water= 75ml
H
3
BO
3
= 30ml
NaOH= 50 ml
Titrant: HCl 0.2N
Distillation time= 4 min
Steam power= 100%
Press the button starting distillation cycle.
References:
AOAC, “Official methods of analysis”, method 981.10
270