Background:
Fish is an essential source of nutrients for human nutrition due to the composition
of proteins, vitamins, and minerals, among other nutrients. Enzymatic hydrolysis represents an
alternative for the use of by-products of the aquaculture industry.
Objective:
We propose to evaluate the effect of stirring speed, temperature, and initial protein concentration
on the degree of hydrolysis of proteins and antioxidant activity of red tilapia (Oreochromis
spp.) viscera hydrolysates.
Methods:
The effect of stirring speed, temperature, and initial protein concentration on the degree of
hydrolysis of proteins and antioxidant activity was evaluated using an experimental design that was adjusted
to a polynomial equation. The hydrolysate was fractioned to determine the antioxidant activity
of the fractions, and functional properties were also measured.
Results:
Stirring speed and protein concentration presented a statistically significant effect (p <0.05)
on all the response variables. However, the temperature did not present a statistically significant effect
on the degree of hydrolysis.
Discussion:
The best conditions of hydrolysis were stirring speed of 51.44 rpm, a temperature of
59.15°C, and the protein concentration of 10 g L-1. The solubility of the hydrolysate protein was high
at different pH, and the hydrolysate fraction with the highest antioxidant activity has a molecular
weight <1 kDa.
Conclusion:
The degree of hydrolysis and the biological activity of red tilapia viscera hydrolysates
(Oreochromis spp.) are affected by temperature, substrate concentration, and stirring speed. The optimal
conditions of hydrolysis allowed to obtain a hydrolysate with antioxidant activity are due to the
peptides with low molecular weight.
Enzymatic hydrolysis of chicken viscera proteins in the presence of an ionic liquid as a strategy to improve the antioxidant properties of the hydrolysates
