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| DETERMINATION OF HYDROGEN PEROXIDE IN MILK BY FOODLAB |
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Hydrogen peroxide can be utilised as a cleaning agent in milk treatment equipment but these procedures must be made in such a way as to impede an eventual contamination of the milk.
Instead, hydrogen peroxide is utilised as a stabiliser of milk, in well defined concentrations in some European countries and America, particularly in certain preparations of hard cheeses as an alternative to pasteurisation.
The FoodLab system permits the determination of H2O2 concentration in milk in a few seconds, without any preventive treatment of the sample, with a very high sensitivity. The reliability and precision of the method are guaranteed by a calibration system that permits the alignment of the instrument utilising standard solutions.
The FoodLab system has been tested via recuperation tests.
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| MATERIALS AND CORRELATION METHODS |
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The FoodLab method is based upon an enzymatic reaction that brings about the formation of a pink substance: its intensity, measured at 505 nm, is directly proportional to the concentration of H2O2 in the sample.
Recuperation tests were carried out on samples of fresh milk: aliquots of milk were added with standard solutions of H2O2 and analysed by the FoodLab system.
Furthermore, five repeatability tests were carried out on four samples.
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| RESULTS AND DISCUSSION |
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| The reference values and the tests carried out utilising the FoodLab system are compared in Tab.1 . The values are comparable and the repeatability of the data is very good, as can be seen by the standard deviation and by the Variation Coefficient calculated for each sample. In Fig.1 , the correlation coefficient of the straight line of regression (r = 0,999) confirms the optimum alignment of the instrument to the reference values. . |
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| Fig.1 -
Correlation between FoodLab method and reference method
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| Tab.1 -
Repeatability test using the FoodLab system
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Ref
ppM |
1,7 |
5,1 |
8,3 |
17,0 |
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1,7 |
5,1 |
8,4 |
17,5 |
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1,8 |
5,2 |
8,1 |
18,1 |
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1,6 |
4,9 |
8,3 |
17,6 |
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1,7 |
5,2 |
8,4 |
17,0 |
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MEAN |
1,7 |
5,1 |
8,4 |
17,8 |
SD |
0,08 |
0,13 |
0,18 |
0,25 |
CV,% |
4,9 |
2,6 |
2,2 |
1,4 |
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| SHORT TABLE |
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Linearity |
Accuracy |
Repeat. |
R2 |
Sensitivity |
Total
analysis
time |
Test/hour |
25 ppM |
±5% |
CV < 3% |
r > 0,99 |
1,5 ppM |
6 - 8 min |
100 |
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Foodlab¬ |
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» A new concept in quality analysis of food.
Foodlab is a quick, reliable and practical system for chemical tests on olive oil, seed oils, alimentary fats, vegetable purées, milk, cheese and other dairy products. |
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| Application Sheet |
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