In order to evaluate the accuracy of the CDR method to test lactose in milk, 6 samples of commercial lactose-free milk from different producers were selected. The samples was stabilised and in 4 of these, an aliquot of whole milk (5% lactose) was added and thus a known amount of lactose.

The accuracy of the CDR FoodLab® method is assessed by determining the correlation between the results of the 10 milk samples obtained by the analyses with CDR FoodLab® and those obtained by the Istituto Zooprofilattico using the HPLC method (High Performance Liquid Chromatography) as provided by the reference method MP 02/050 rev.6- 2018.

The table shows data obtained with two different CDR FoodLab® instruments, used by two different operators in order to also assess the reproducibility of the CDR method.

 

 

CDR FoodLab® 1 
(%)

CDR FoodLab® 2 
(%)

CDR FoodLab®  average (%)

IZS Lab. (%)

Sample 1

Fresh

0,04

0.03

0,03

0,030

Sample 2

UHT

0,01

<0,01

0,01

<0,025

Sample 3

UHT

0,03

0,02

0,02

<0,025

Sample 4

Fresh

0,13

0,11

0,12

0,126

Sample 5

Sample 2 + 0,35%

0,35

0,36

0,35

0,450

Sample 6

UHT

0,18

0,19

0,19

0,179

Sample 7

UHT

0,02

0,03

0,02

<0,025

Sample 8

Sample 7 + 0,1%

0,11

0,12

0,12

0,147

Sample 9

Sample 6 + 0,1%

0,26

0,27

0,27

0,315

Sample 10

Sample 3 + 0,1%

0,12

0,14

0,13

0,143

 

...

Conclusions

The two methods provided highly correlated results (R2= 0,990) confirming the excellent accuracy of the CDR method.

ArticleData image
Lactose test correlation report

Download the Correlation study between the CDR FoodLab® method for lactose determination and the reference method MP 02/050 rev.6- 2018 carried out by a major Istituto Zooprofilattico Sperimentale.

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