Proteins are long chains of amino acids (>100) joined by peptide bonds. Hydrolysis is the process whereby these bonds are broken forming smaller chains of amino acids depending on the type of enzyme used and the processing conditions. The polypeptides (50-100 amino acids) and peptides (<50 amino acids) formed during this process determine the functional and nutritional characteristics of the hydrolysate.

Hydrolysis mimics part of the process that takes place in the small intestine where various enzymes break down protein into smaller peptide chains. This means that hydrolysed protein is absorbed in about half the time of intact protein sources. In fact, tri- and di-peptides are absorbed more rapidly than free form amino acids.

Hydrolysed protein is often a euphemism for hydrolysed collagen protein - gelatin, good old fashioned jelly. Most often found in protein bars (check those labels folks), gelatin, although technically a protein, is an incomplete protein that is also poorly digested. In contrast, hydrolysed whey protein isolate (HWPI) and hydrolysed caseinate (HC) are rapidly digested high quality proteins which essential amino acids and micro-fractions intact.

The two major features of hydrolysates are the degree of hydrolysis and molecular weight. The degree of hydrolysis represents the percentage of peptide bonds available to a particular enzyme that have been broken. The degree of hydrolysis for wpi ranges from 5% to 30% and for caseinate up to 40%. Bitter taste is a hallmark of hydrolysis and bitterness increases with the degree of hydrolysis.

Average molecular weight also describes hydrolysed protein although a molecular weight profile gives a more accurate characterisation. Whey protein isolate has an average molecular weight of about 26kDa (MF WPI) to 30kDa (IX WFI). In contrast, the average molecular weight of a hydrolysed milk proteins ranges from 500Da to 5kDa.

Hydrolysed Whey Protein Isolate DH10
Degree of hydrolysis 9% Average molecular weight 3300Da more
Hydrolysed Whey Protein DH17
Degree of hydrolysis 17% Average molecular weight approx 1500Da more
Hydrolysed Whey Protein Isolate DH17 Ultra
Degree of hydrolysis 23% Average molecular weight approx 800Da more
Hydrolysed Casein Protein
Degree of hydrolysis 9% Average molecular weight approx 3000Da more