Milk and dairy products

Ammonia is an important indicator of the quality of milk, in all stages of the production chain. In fact, the ammonia is a metabolite of microbial activity and increases with the amount of bacteria in milk.

Ammonia test in milk and dairy products

CDR FoodLab® is the chemical analyzer for quality and process control that allows you to determine a wide range of parameters of many foods, animal feeds and pet foods. 

Endpoint analysis. Analysis time: [uni]. Analysis sessions with multiple samples are possible up to a maximum of 16 tests for CDR FoodLab® and 3 tests for CDR FoodLab® Junior.&nbsp;<h3>Sample treatment</h3>Whole or skimmed milk: use as is. Use the “NH3 milk” curve. Cheese: Weight 5 gr of sample, crumble it and mix in 45 mL of distilled water. Centrifuge or filter in order to separate the larger parts. Rapidly process the sample because ammonia tends to increase. Use the “NH3 cheese” curve. Fresh cream: Take 4 mL of cream in a centrifuge tube, add 100 uL of HCL (diluted 1:10), shake it and centrifuge for 5 minutes. Take the aqueous solution and filter it, if necessary. Use the “NH3 milk” curve to test.

Method

The ammonium ions react with a phenolic derivative and form a blue-green colored complex whose intensity, measured at 700 nm, is directly proportional to the concentration of ammonia in the sample.

Test principle

Reaction involved in the analysis of ammonia in milk and dairy products

The Poligny ACTALIA (France) reference laboratory, specialising in food analysis, performed an evaluation study: the <a href="/cdrfoodlab/validations/actalia-cdrfoodlab-evaluation-milk">determination of ammonia on whey was performed with CDR FoodLab® and with the enzymatic reference method (NF V 04-217)</a>. The correlation between the CDR FoodLab® method and the reference method was found to be good,&nbsp; considering the type of analysis and the difficulty in performing the reference methodology, obtaining an R2&nbsp;= 0.9265.

Calibration curve

The determination of ammonia on whey was performed with CDR FoodLab® and with the enzymatic reference method (NF V 04-217). The correlation R² = 0.9265

<a target="_blank" rel="noopener noreferrer" href="https://www.cdrfoodlab.com/cdrfoodlab/validations/validation-cdrfoodlab-ammonia-milk">Comparative tests</a>, on samples of whole milk, performed between the reference method and the CDR FOODLAB® method, made in a leading company of production of milk, have confirmed a very good correlation between the two systems.

Reagent test Kits

Measuring range

CDR FoodLab® the analyzer for quality control of food, animal feeds and pet foods. Top version

CDR FoodLab®

CDR FoodLab® the analyzer for quality control of food, animal feeds and pet foods. Junior version