Impact of Pulsed Electric Fields and pH on Enzyme Inactivation and Bioactivities of Peptic Hydrolysates Produced from Bovine and Porcine Hemoglobin

Abstract

The production of bioactive peptides from hemoglobin via peptic hydrolysis is a promising alternative to valorizing slaughterhouse blood proteins. Nevertheless, it has some limitations such as low yield, high cost of enzymes, and the use of chemical reagents. The latter is aggravated by the pH increase to inactivate the enzyme, which can affect the bioactivity of the peptides. Thus, this study aimed to evaluate the effect of pulsed electric fields (PEF) on the pepsin inactivation and biological activities (antimicrobial and antioxidant) of hemoglobin hydrolysates. Bovine (Hb-B) and porcine (Hb-P) hemoglobin were hydrolyzed with pepsin for 3 h and treated with PEFs to inactivate the enzyme. The degree of hydrolysis (DH) did not show significant changes after PEF inactivation, whereas peptide population analysis showed some changes in PEF-treated hydrolysates over time, suggesting residual pepsin activity. PEF treatments showed no significant positive or negative impact on antimicrobial and antioxidant activities. Additionally, the impact of pH (3, 7, and 10) on bioactivity was studied. Higher pH fostered stronger anti-yeast activity and DPPH-scavenging capacity, whereas pH 7 fostered antifungal activity. Thus, the use of hemoglobin from the meat industry combined with PEF treatments could fit the circular economy concept since bioactive peptides can be produced more eco-efficiently and recycled to reduce the spoilage of meat products. Nevertheless, further studies on PEF conditions must be carried out to achieve complete inactivation of pepsin and the potential enhancement of peptides’ bioactivity.

Propelling of Enzyme Activity by Using Different Triggering Strategies: Applications and Perspectives

“…PEF processing involves applying short pulses (microseconds to milliseconds) of high voltage electric field to materials placed between two electrodes, and the applied electric field strength can vary from 10 to 80 kV/cm. , Although it requires large specific energy to inactivate enzymes compared to microbial inactivation, PEF has been reported to be an effective strategy to significantly inactivate the most undesirable enzymes in the preservation of food products. This approach allows changing the physicochemical and biochemical properties of proteins by affecting the three-dimensional structural elements of proteins due to the interaction between the electric field and their dipole moments, as well as the ionization of the radical groups of carboxylic groups (−COO – ), amino groups (−NH 3 + ), and electrically charged residues (lysine, arginine, histidine, aspartic acid, and glutamic acid). , However, available evidence has reported that low-intensity exposure to PEF can also induce the activities of useful enzymes. This method is in trouble with two major disadvantages in terms of use.…”

“…This approach allows changing the physicochemical and biochemical properties of proteins by affecting the three-dimensional structural elements of proteins due to the interaction between the electric field and their dipole moments, as well as the ionization of the radical groups of carboxylic groups (−COO − ), amino groups (−NH 3 + ), and electrically charged residues (lysine, arginine, histidine, aspartic acid, and glutamic acid). 102,104 However, available evidence has reported that low-intensity exposure to PEF can also induce the activities of useful enzymes. This method is in trouble with two major disadvantages in terms of use.…”