Protein Quality Determination is one of the most poorly understood areas of the Canadian and US food regulations. Some of the difficulty stems from the lack of good data that will clarify protein quality for ingredients to be used for calculation purposes. And the reason for the lack of data is the high cost and complexity of Protein Quality Analysis.
But don’t get discouraged… We have prepared for you a summary of a simple 3 step process to get you underway on the Protein Quality determination for your food product starting with a quick explanation of PDCAAS and PER:
PDCAAS and PER are both recognized measurements for the quality of protein in food products. PDCAAS is determined based on a combination of the measured Protein Digestibility and the Amino Acid Composition of the food relative to requirements set out by the World Health Organization (WHO), Food and Agricultural Organization of the United Nations (FAO) and the United Nations University (UNU).
As per Canadian Food Regulations: PER = PDCAAS x 2.5, where 2.5 is the PER of Casein.
So, PER is a measurement of the relative quality of a protein in relation to the quality of Casein, the protein in milk.
In Canada, we are obliged to determine the Protein Rating of a food in order to determine the allowance for protein quality claims. If the protein rating is >20, this food will then qualify as a “Source of Protein”, or “High in Protein”. The basic overall formula for the determination of Protein Rating is simple :
Protein Rating = PER (Protein Efficiency Ratio) X Quantity of Protein in a Reasonable Daily Intake (RDI) of that food . (1)
So, how do we calculate this?
Step 1: Determine the Quantity of Protein in the RDI.
Here is the formula to use for determining this quantity when the Protein in your food is all, or nearly all, coming from a Protein supplement or composite.
Quantity of Protein in RDI = RDI X %Protein Supplement used in the product X %Protein in the Protein Supplement .
The FDA has provided figures for Reasonable Daily Intakes of many foods in Schedule K. (2) You can find this schedule on the CFIA website. For any food that is not listed, we are to use the quantity in a single serving of the food as the Reasonable Daily Intake. As examples, the RDI for bread is 150g (5 slices) and the RDI for soup that is ready to consume is 200g, as listed. If you had a packaged muffin that weighed 100g, the RDI for that product would be 100g.
So, here is an example of how to complete this calculation:
1. If the RDI for a food is 200g, such as ready to consume soup, and you are adding 6.5% of a Protein component such as Profi Pro that contains 78% protein
Quantity of Protein in the RDI = 200g X 6.5% X 78% = 10.14g.
Step 2: Determine is the PER for the food.
Here is where the difficulty normally lies. Health Canada has provided a list of PER values for about 50 foods. (3) However, this list is rather short when we consider all of the protein options available today. You could have your product tested for PER, but this is expensive, it takes time and depending on what you have used for your protein source, you may find notable variation from sample to sample.
This is where our vegan protein powder PROFI Pro can help you out… It is easy to incorporate into most foods, neutral tasting,
and PROFI Pro has a PDCAAS value of 84% and a PER of 2.1.
Step 3: Calculate the Protein Rating of the food.
Here is an example using the calculated figures from Step 1 above:
1) If you have added 6.5% PROFI Pro to your food product that has a Reasonable Daily Intake of 200g, and since PROFI Pro is 78% Protein with a PER of
2.1 : Protein Rating = PER X Quantity of Protein in one RDI of that food
= 2.1 X 10.14g.
= 21.3 and this is >20. So, you can make a “Source of Protein” or “High Protein” claim on your food package.