In this article we report the results of an analysis commissioned by the country at the University of Ferrara, to determine the protein content of ten milk protein supplements. 
The samples were chosen in order to obtain a representative picture of the market, thus examining both domestic and foreign products, more or less known supplements and of different price classes. To avoid interference with the analyzes, only whey protein supplements (Whey) and / or caseins were chosen, variously flavored but without the addition of specific amino acids (creatine, etc.). Most of the protein supplements were vanilla flavored, since they are generally those with higher protein content than other flavored products (cocoa, hazelnut, banana, etc.).
The analyzes of the protein content were carried out according to the official Kjeldahl method, deliberately keeping a high tolerance on the measured value (CV% <4). For the sake of fairness, we do not report the commercial names of the products, nor the manufacturing companies since:
the sample examines too few products compared to those on the market; consequently, also considering possible conflicts of interest, the publication of trade names could be understood as an attempt to penalize specific companies over others.
Protein Supplement Analysis Results
| No. | Protein value label | Protein value detected | Waste % | Price per 100 g of product * | Price per effective 100g of protein ** | Origin | Raw material declared |
| 1 | 69 | 66,04 | --4,29 | 4,41€ | 6,67€ | USA | Concentrated and isolated whey proteins, chocolate |
| 2 | 76 | 69,63 | --8,38 | 3,70€ | 5,31€ | EU | Whey protein, chocolate / coconut |
| 3 | 90 | 86,05 | --4,39 | 4,40€ | 5,11€ | ITA | Soluble calcium caseinate, banana |
| 4 | 77 | 72,25 | --6,17 | 4,74€ | 6,56€ | USA | Concentrated and isolated whey proteins, vanilla |
| 5 | 88 | 81,64 | --7,23 | 5,50€ | 6,74€ | ITA | Ultrafiltered proteins, concentrated proteins, egg white, vanilla |
| 6 | 88 | 83,96 | --4,59 | 5,40€ | 6,43€ | USA | Ultra-microfiltered whey protein isolate, vanilla |
| 7 | 82 | 79,06 | --3,59 | 4,57€ | 5,78€ | USA | Isolated, concentrated, hydrolyzed vanilla whey proteins |
| 8 | 77 | 70,23 | --8,84 | 4,19€ | 5,97€ | USA | Isolated, concentrated, hydrolyzed vanilla whey proteins |
| 9 | 81 | 75,42 | --7,00 | 4,83€ | 6,40€ | ITA | Instantized whey proteins, micro and ultrafiltered whey proteins, vanilla |
| 10 | > 90% | 81,30 | > - 9,67 | 2,10€ | 2,58€ | GB | Undenatured whey protein, chocolate |
* calculated on the basis of the list price and the net weight declared on the label (ranging from a minimum of 725 to a maximum of 1000 grams in the various protein supplements) ** calculated on the basis of the list price, the net weight declared on the label and the protein content resulting from the analyzes Certification | |||||||
COMMENT: from the data shown in the table it is clear that all the products analyzed overestimate the real protein content of the product on the label, remaining within the maximum deviation allowed by the Ministry of Health (± 15%). The cheapest product has the greatest deviation (- about 10%); however, even by correcting the price for the real protein content, it retains a distinct convenience compared to the others.
There are no substantial differences between domestic products and foreign products, relative to the difference between declared protein content and actual protein content.
