Date: 25/11/2019

Why to hydrolyze a protein? What are the advantages that it can bring from a nutritional point of view?

The key to this question helps answer why enzymatic hydrolysis is advantageous to the diet of several animal species. This type of hydrolysis can generate bioactive peptides that bring health benefits that go far beyond basic nutrition.

In addition, protein hydrolysates also carry functional properties capable of enhancing fundamental characteristics of various formulations.

Therefore, in this blog post, we will understand the mechanism of enzymatic hydrolysis and how it is able to generate so many benefits.

Bioactive peptides: why are they so desirable?

 Proteins are macromolecules essential to life. Its fundamental structure consists of amino acid chains linked by a peptide bond.

The difference in the sequence of these amino acids is a differentiating factor that will define the biological function of the protein.

These chains increase their complexity and, consequently, their molecular weight by organizing themselves into secondary, tertiary and quaternary structures.

In contrast, peptides can be defined as amino acid sequences that do not have all the structural arrangements of proteins, therefore, have lower molecular weight.

Some of them perform certain functions which, although not essential, bring very important benefits to the organism.

Among these functions we have performance with antimicrobial, antioxidant, antihypertensive, immunomodulatory, anti adipogenic, among others.

This type of peptide receives the name of bioactive peptide and, in recent decades, has drawn the attention of researchers from around the world and aroused commercial interest.

Specifically at the commercial level, bioactive peptides can be used to strengthen animal feed of various species, including fish, pigs and pets.

The inclusion of this type of peptide in the animal diet is one more way to ensure a healthy development for those species. As, for example, through the favoring of absorption of other nutrients by the animals.

One property of bioactive peptides that has had a more recent discussion refers to antioxidant activity.

The presence of free radicals in aerobic organisms is common to the breathing process. However, the excessive accumulation of these species in the organism causes cellular damage that is associated with the development of chronic diseases such as diabetes, Alzheimer’s, cardiovascular diseases and cancer.

The consumption of substances with antioxidant properties is able to inhibit free radicals, reducing the chances of developing the mentioned diseases.

The literature mentions that some bioactive peptides exhibit antioxidant property. This will depend on factors such as type of protein, enzyme used, hydrolysis degree and substrate pretreatment.

One way to obtain bioactive peptides is through enzymatic hydrolysis

This process is characterized as a chemical reaction catalyzed by an enzyme that uses water to break a molecule into two or more fractions.

Therefore, when applied to an environment containing proteins, they will be broken down into smaller amino acid chains, the protein hydrolysates.

Because the enzymes have specificity and selectivity, it is possible to control the process conditions according to the type of hydrolysate desired.

The process conditions (temperature, pH, enzyme/substrate ratio, among others) differ according to the type of enzyme and substrate.

When adjusting an enzymatic hydrolysis process, it is important for the professional to have in-depth knowledge of all reaction factors, especially with regards to the enzyme specifically. This knowledge will be essential to obtain a good rate of reaction speed and to make the most of enzyme efficiency.

For example, each enzyme has an optimal range of pH and temperature. That is, if the reaction is performed within this range, the enzyme efficiency will be maximum. It is also necessary to set the enzyme/substrate ratio correctly, since this factor is decisive for the size of the formed peptide chains.

Why use protein hydrolysates?

Firstly, due to its high coefficient of apparent digestibility for several animal species, usually above 90%.

Another reason is the peptides from hydrolysed proteins that can be absorbed 10 times faster than free amino acids because they do not compete for the same site of absorption.

The protein hydrolysates have functional properties that guarantee food and feed with better appearance, texture, taste and convenience.

Among the functional properties that are improved by the addition of protein hydrolysates, we can mention solubility, water retention capacity and emulsifying capacity.

The solubility of protein hydrolysates will depend on the number of polar and nonpolar groups located in the molecule, as well as an influence of smaller scale of the pH of the environment and of the presence of salts.

The great advantage of hydrolysates in relation to the intact proteins in regards to solubility, are the smaller chains and amino groups and ionizable carboxyl of the newly exposed amino acids, which ensures a greater hydrophilicity.

On the other hand, the water retention capacity is especially desirable for meat products, to maintain moisture during unitary operations common to these products, such as cutting, heating, crushing, among others.

This property is more dependent on pH and ionic environment, therefore, it will be determined by the ionizable groups present in the hydrolysate and also by the existence of salts in the environment.

At the same time, emulsification is the ability to decrease the interfacial tension between two or more immiscible liquids.

Hydrolysates can have this ability improved through the manipulation of the extent of hydrolysis, so that there is a balance between hydrophilic and hydrophobic groupings of the molecule.

Chicken protein hydrolysate and animal nutrition

Chicken protein hydrolysate is derived from chicken meat by-products.

In this particular product, the use of enzymatic hydrolysis allows obtaining bioactive peptides of low molecular weight which, in addition to the functional properties already mentioned, also specially benefits animal nutrition.

Chicken protein hydrolysate peptides are capable of increasing the absorption of the ingredient in which they are inserted into, as well as benefiting the immune system and antioxidant activity, contributing to a healthy development and increasing the survival rate.

This hydrolysate is characterized as a versatile ingredient that can be part of the nutrition of several species:

  • When used in tilapia feed, for example, chicken protein hydrolysate has a digestibility of over 90%. Surpassing fishmeal, which has 82%. In addition, the palatability of the hydrolysate is also 10% higher than fishmeal. This attracts greater consumption by animals and avoid waste and its related problems.
  • Pigs, on the other hand, have a limiting organism in some aspects, such as the impossibility of releasing protein from fibers, for example. Thus, they require a diet based on ingredients with high digestibility and palatability. The chicken protein hydrolysate guarantees both characteristics for pig feed. A study has even found that the addition of 6% of this ingredient to the diet of weanling pigs promoted a significant increase in animal growth.
  • For cats, chicken protein hydrolysate also has good digestibility, contributing to a better quality of life for cats and avoiding waste.


The use of enzymatic hydrolysis to obtain protein hydrolysates rich in bioactive peptides is a growing process.

In addition to providing versatile products, with applications ranging from use in food products to fortification of ingredients for animal nutrition, it is also a process with great environmental appeal, as it allows the replacement of the use of chemical reagents with high capacity of pollution.

Within this segment, chicken protein hydrolysate stands out as an effective alternative to the diet of some animal species.