D-3-hydroxybutyric acid test in Egg and Egg Products
The pasteurization of egg products is based on the use of not high temperatures, because egg proteins are sensitivity to heat. For this reason, the use of bad eggs, increases the health risk and reduces the shelf-life of the fresh egg products. The use of incubated or decayed eggs can be detected verifying the presence of some organic acids indicative of metabolic products and microbial decomposition such as succinic acid, lactic acid and D-3-hydroxybutyric acid.
The best method currently highlighting this fraud is the test of D-3-hydroxybutyric acid, very low in fresh eggs (<1mg/kg), but much higher in the wastes of incubator. The analysis is generally carried out by extraction and gas chromatography. The N.853/2004 REGULATION (CE) states that the level of D-3-hydroxybutyric acid in egg products should not exceed 10mg/kg of dry matter.
Method
Test type: kinetic
Test time: 6 minutes.
Analysis sessions with multiple samples are possible up to a maximum of 16 tests for CDR FoodLab® and 3 tests for CDR FoodLab® Junior.
Sample treatment
Yolk: Dilute one part of sample with one part of distilled water and proceed as described for the mixed egg.
Mixed eggs: take 10 grams of mixed sample in a plastic glass and add 1 g of polymer. Stir for a few minutes (e.g. with magnetic stirrer). Transfer part of the solution obtained in a centrifuge tube and centrifuge for 5 minutes. Use the clear solution. If the solution is not sufficiently clear, continue in this way: add directly into the centrifuge tube, about 0,5 g of polymer. Shake well and centrifuge again.
Test principle
The D-3-hydroxybutyric acid reacts, by an enzymatic reaction with the NAD+ and induces the formation of apink color whose intensity, measured at 505 nm, is directly proportional to the concentration of D-3-hydroxybutyric acidin the sample. The result is expressed as ppm of D-3-hydroxybutyric acid.
...
Calibration curve
Comparative tests on mixed egg samples where a standard of D-3-hydroxybutyric acid has been added, verified with the CDR FoodLab® method, confirmed a very good alignment.
...
Reagent test Kits
Measuring range
| Analyses | Measuring range | Resolution | Repeatability |
|---|---|---|---|
| D-3-Hydrox. ac. - egg mixture | 0.5 - 15 ppm | 0.1 ppm | 0.5 ppm |
| D-3-Hydroxybutyric acid - egg yolk | 0.5 - 15 ppm | 0.1 ppm | 1 ppm |
The Analyzers for quality control of egg products
CDR FoodLab®
- Complete analysis panel, supplied already configured
- Up to 16 determinations simultaneously
- Possibility of carrying out analyses of the same sample
- Integrated printer
- Full connections (LAN - USB - Bluetooth barcode/QR code reader)
CDR FoodLab® Jr
- Partial analysis panel, supplied configured with 3 analyses of your choice, implementable
- Up to 3 determinations simultaneously
- Wireless connection to external printer
- USB connections