Elements within the Nutrition Facts Table
The protein rating of a food is based on the protein content in a Reasonable Daily Intake of that food as sold as per Schedule K of the FDR.
Protein Rating is calculated by multiplying the quantity of protein present in a Reasonable Daily Intake of the food by the quality of the protein, which is the Protein Efficiency Ratio (PER) of the food.
Protein Rating = Protein in a Reasonable Daily Intake x Protein Efficiency Ratio (PER)
If there is no Reasonable Daily Intake specified for the product in Schedule K of the FDR, then the Reference Amount (RA) for the food may be used. When the food has no RA, the product is evaluated on a case-by-case basis.
Established PER's are listed in the table Protein Efficiency Ratios. For those not already established, it is the manufacturer's responsibility to determine the PER. The official method for determining the PER is Method FO-1, October 15, 1981 - PDF (213 kb). It is Health Canada's position that the official method must be used to support any protein claim. However, a manufacturer that sells a product with no established PER can use another method to determine protein quality in relation to casein, such as the PDCAAS method (protein digestibility - corrected amino acid score) and it would be advisable for the manufacturer to keep on file the information and references used to make that determination. If the protein claim is in question, then Method FO-1 would be used for verification.
The PER of two sources cannot be added to calculate the total PER of a food with multiple sources of protein. If the total PER of a food with multiple protein sources/mixture of proteins is unknown, it can be estimated by determining the PDCAAS of the mixture of proteins in the final product as described in the FAO/WHO publication on the PDCAAS method - PDF (3,959 kb). The PDCAAS obtained can be used to estimate the PER and then this can be used in the protein rating calculation for the purpose of making a claim.
The PER may be estimated from the PDCAAS using the following formula:
PDCAAS for food x 2.5 = estimated PER for food
Calculating Protein Ratings
Example - Calculating the Protein Rating of White Bread
Percent (%) Protein = 8.4
Reasonable Daily Intake = 150 g (5 slices)
Protein in a Reasonable Daily Intake = 0.084 X 150 g = 12.6 g
PER = 1.0
Protein Rating = 12.6 X 1.0 = 12.6
Example - Calculating the Protein Rating of Whole Egg
Percent (%) Protein = 12.8
Reasonable Daily Intake = 100 g (2 eggs)
Protein in a Reasonable Daily Intake = 0.128 X 100 g = 12.8 g
PER = 3.1
Protein Rating = 12.8 X 3.1 = 39.68
Protein Efficiency Ratios
|Food||Protein Efficiency Ratio (PER) 1|
|Beans, navy (dry)||1.51|
|Beef or veal, muscle||2.7|
|Chick peas, cooked||2.32|
|Gelatin or hydrolysed collagen||0|
|Lentils, cooked (all other lentils)||0.3|
|Lentils, whole green||1.3|
|Macaroni & cheese||2.1|
|Muscle Meats (bison, lamb, etc)||2.7|
|Peas, split yellow||1.42|
- The official method for determining the protein efficiency ratio is from Health Canada's Health Protection Branch Method FO-1, October 15, 1981.
- Samples within each market class from the largest volume processors catering to the Canadian consumer market were composited and conventionally cooked.
Certain requirements related to protein content and protein ratings apply for simulated meat products. Please refer to the appropriate section for information.
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