The RIDASCREEN® Milk Concept

Analytical test kits for ensuring milk-free food production

Which test for what?

• The RIDASCREEN®FAST Milk (Art. No. R4652) is a sandwich enzyme immunoassay to quantify milk proteins in food containing whey, milk or milk powder such as sausages, ice cream, chocolate, bakery goods, cake and bread mix, soups, sauces, dressings and beverages (juice, wine, beer). The assay results are quantitative if the sample contains milk or milk powder. If the milk protein composition of the sample is not known and the milk protein ratio is different than the natural ratio in milk (e.g. a sample primarily consisting of whey), the results may be underestimated.
• The RIDASCREEN®FAST Casein test (Art. No. R4612) is suitable for foods, which may predominantly contain casein or caseinates. When the casein content of the sample is known, it can be converted to milk protein. If cow’s milk has been added to the food or if the food contains contamination from cow’s milk, the casein content is 2.6%. Also, whey products, which consist mainly of BLG could contain traces of casein and thus can be analyzed. The test detects the actual proportion of the casein contamination in the whey sample. The amount of contamination in relation to BLG is not known. Therefore, the measured casein content of whey samples can not be converted to the milk concentration. However, a positive result on casein indicates a milk-contamination of food. The presence of milk protein has to be declared on the food label.
• The RIDASCREEN®FAST β-Lactoglobulin test (Art. No. R4912) is suitable for food, which can primarily contain whey protein. The amount of BLG is a correlation to the available amount of whey in the food and thus, indicates the presence of milk protein. The food has to be labeled. Caseins and caseinates are not producible without BLG parts. An existing contamination can be detected in the test. The level of contamination in relation to casein is not known. Therefore, the measured BLG of a Casein sample could not be converted to the milk concentration.
• The RIDASCREEN® β-Lactoglobulin test (Art. No. R4901) is suitable for hydrolyzed milk products, especially for hypoallergenic baby formula, because the competitive format is capable to detect small protein fragments (one epitope) in highly hydrolyzed milk products.

In addition to the detection of traces of milk in food, R-Biopharm offers qualitative tests for process and hygiene monitoring by lateral flow devices. The Bioavid Lateral Flow Milk rapid test (Art. No. BL613-25) is suitable for a qualitative process control under the allergen management according to HACCP (Hazard Analysis and Critical Control Points). Surfaces can thus be examined for milk contamination during food production to detect and prevent cross-contamination. The effectiveness of cleaning of equipment and facilities can be reviewed.

Conversions according to the food composition

• Conversion of casein into milk:
  The result of the RIDASCREEN®FAST Casein test (Art. No. R4612) is given in mg/kg casein and can be converted into milk or milk protein, if the sample contains casein. If samples contain cow’s milk the casein content is 80 % of the milk protein, which in turn accounts for 3.2 % of the milk. Example: 10 mg/kg (ppm) casein were measured; 12.5 ppm milk protein were calculated (10 ppm casein x 100 % / 80 %) and 390.6 ppm milk (12.5 ppm milk protein x 100 % / 3.2 %).
• Conversion of β-Lactoglobulin (BLG) into milk:
  The result of the RIDASCREEN®FAST β-Lactoglobulin test (Art. No. R4912) is expressed in mg/kg BLG and can be converted into milk or milk protein, if the sample contains whey or BLG. If samples contain cow’s milk the BLG content is 10 % of milk protein, which in turn accounts for 3.2 % of the milk. Example: 1 mg/kg (ppm) BLG was measured; 10 ppm milk protein was calculated (BLG 1 ppm x 100 % / 10 %) and 312.5 ppm milk (10 ppm milk protein x 100 % / 3.2 %).
• Conversion of milk protein into milk:
  The result of the RIDASCREEN®FAST Milk test (Art. No. R4652) is expressed in mg/kg of milk protein and can be converted into milk. The conversion factor of milk protein into milk is 31.25. If the measured milk protein value is multiplied by the factor of 31.25, the result is obtained in mg/kg (ppm) of milk. Example: 1 mg/kg (ppm) milk protein x 100 % / 3.2 % = 31.25 ppm milk.
• Conversion of milk powder into milk:
  Milk powder equates to about 10 % of milk because milk contains about 90 % of water. If the value is measured in milk powder and multiplied with the factor of 10, the result is expressed in milk. Example: 1 ppm milk powder x 100 % / 10 % = 10 ppm milk.