Obtaining multifunctional bioactive peptides through enzymatic hydrolysis of proteins from the larvae of the black soldier fly (Hermetia illucens)

The improvement of the biological and technological properties of insect proteins has been the subject of studies for their inclusion in human food and animal feed. This work aimed to produce bioactive peptides with multifunctional properties by enzymatic hydrolysis of proteins from the larvae of black soldier fly (Hermetia illucens) using an experimental design of mixtures in which three commercial proteases were applied alone or in binary/ternary combinations. The hydrolyzed proteins were evaluated to their antioxidant, antidiabetic and antihypertensive properties. In addition, the samples with the highest bioactivities were fractionated by ultrafiltration. The results showed that the combination of Flavourzyme (2/3), Alcalase (1/6) and Neutrase (1/6) resulted in protein hydrolysates with higher antioxidant potential, as follows: ABTS (588.04 µmol TE/g), DPPH (30.15 µmol TE/g) and FRAP (76.29 µmol TE/g); compared to the non-hydrolyzed sample, these results represented increases of 48, 11 and 14%, respectively. For antidiabetic properties, the combination of Flavourzyme (1/2) and Alcalase (1/2) resulted in peptides capable of inhibiting 45% the α-amylase activity. The antihypertensive potential of the hydrolysates, measured by the ability of the peptides to inhibit the angiotensin-converting enzyme (ACE) activity, showed that the combination of Alcalase (1/2) and Neutrase (1/2) resulted in samples capable of inhibiting up to 75% the ACE activity. From the results, the ternary combination of Flavourzyme (2/3), Alcalase (1/6) and Neutrase (1/6) was chosen as the best condition to produce bioactive peptides with multifunctional properties. Ultrafiltration demonstrated that protein hydrolysates with molecular mass between 5-3 kDa have greater antioxidant activity for the ABTS and DPPH methods, while the fraction between 30-10 kDa has greater activity in the FRAP method. The results obtained in this work intend to contribute to the expansion of knowledge about insect proteins and their multiple uses.