First, let’s take a look at the protein content of these two protein powders. This is the simplest and crudest evaluation. That is, compare two protein powders of the same weight, which protein content is higher.
After the Kjeldahl method, the protein conversion factor of whey protein was 6.38, and that of soybean protein isolate was 5.71.
(Kjeldahl method: a commonly used method in analytical chemistry to determine the nitrogen content of organic compounds. Since the nitrogen content of protein is relatively constant, the protein content can be calculated from its nitrogen content, so it is also a classic protein quantification method. )
Of course, it is unscientific to simply look at the protein content, we also have to look at the ratio of amino acids. Modern nutrition emphasizes the balance of amino acids. The deficiency or excess of certain amino acids will affect the value of protein powder. In this regard, scholars have specifically studied the composition of the two protein powders and the ratio of essential amino acids required by the human body, and obtained the amino acid ratio coefficients of the two protein powders.
From the perspective of nutritional value, whey protein is better than soy protein, whether it is protein content or amino acid ratio, and is more suitable for the human body.