Evaluation of the Antioxidant and Antimicrobial Activities of Porcine Liver Protein Hydrolysates Obtained Using Alcalase, Bromelain, and Papain

Abstract

In order to make the by-products generated from the porcine industry more valuable, pig livers were used in this trial to obtain protein hydrolysates. Three proteases (alcalase, bromelain, and papain) were utilized for enzymatic hydrolysis with two different durations, 4 and 8 hours. Ultrafiltration process was used for the recovery of the extracts, employing three different membrane pore sizes (30, 10, and 5 kDa). The porcine livers contained considerable amounts of protein (19.0%), considering they are almost composed of water (74.1%). The antioxidant activity of the obtained hydrolysates was investigated using four antioxidant methods (2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2-2′-Azino-di-[3-ethylbenzthiazoline sulfonate] (ABTS) radical scavenging activity, ferric reducing antioxidant power assay (FRAP), and oxygen radical absorbance capacity assay (ORAC)). Antibacterial properties were also measured against Gram-negative and Gram-positive bacteria. Results indicated that the three studied factors (type of enzyme, membrane pore size, and time) significantly affected the parameters evaluated. Hydrolysates obtained at 8 hours with alcalase had the best antioxidant properties. The 30 kDa alcalase extracts exhibited the highest DPPH (562 µg Trolox/g), FRAP (82.9 µmol Fe2+/100 g), and ORAC (53.2 mg Trolox/g) activities, while for ABTS the 10 kDa alcalase showed the higher values (1068 mg ascorbic acid/100 g). Concerning the antibacterial activity, 30 kDa hydrolysates obtained with bromelain for 4 hours exhibited the highest antimicrobial capacity, providing an inhibition of 91.7%.

A Review on Health-Promoting, Biological, and Functional Aspects of Bioactive Peptides in Food Applications

“…However, other sources such as poultry by-products (bones, feet, and skin) have emerged owing to regulation, religions restrictions, or culture traditions [ 72 ]. Several types of enzymes have been tested for their extraction such as Alcalase, bromelain, flavourzyme, papain, or pepsin, with papain, pepsin, and Alcalase being those that reported the most successful results for releasing antioxidant biopeptides from animal tissues [ 73 , 74 ]. In this regard, López-Pedrouso et al [ 43 ] found that the use of Alcalase in the enzymatic hydrolysis of porcine liver displayed better results than those obtained with bromelain, flavourzyme, and papain.…”

Measurement of Antioxidant Capacity of Meat and Meat Products: Methods and Applications

“…In this case, the HORAC test was used to ensure the obtaining of functional proteins with good antioxidant capacity, which would make it possible to avoid the excessive amounts of antioxidant additives necessary during storage. For their part Borrajo et al [ 109 ] employed the ORAC, FRAP, DPPH • , and ABTS •+ techniques to determine the antioxidant capacity of porcine liver protein hydrolysates obtained through different conditions (enzymes, times, and filtering). With these four tests, they reported that the ideal conditions for obtaining peptides with antioxidant capacity were the use of Alcalase enzyme with subsequent ultrafiltration through a 30 kDa membrane.…”

The identification and characterisation of novel bioactive peptides derived from porcine liver

“…Once the peptide sequences have been identified they can be cross-checked with databases containing known BAP sequences and/or identify known BAP sequences present in larger peptides or in proteins. Examples of types of BAP activities researched in this fashion are ACE inhibition ( Lafarga et al., 2017 ), antioxidant activity ( Bechaux et al., 2020 ; Borrajo et al., 2020 ; López-Pedrouso et al., 2020 ; Yu et al., 2017 ), immunomodulating activity, and antimicrobial activity ( Borrajo et al., 2020 ; Capriotti et al., 2015 ).…”