Application of Microbial Proteases to Obtain Egg Yolk Protein Hydrolysates With Antioxidant and Antimicrobial Activity

Abstract

S u m m a r yNatural antioxidants with high safety and long-term effect are subject of many studies because they are an alternative to chemical antioxidants which, in larger quantities, can be toxic. One type of natural antioxidants may be food-derived peptides.The aim of this study was to obtain antioxidant and antimicrobial peptides from egg yolk phosvitin and immunoglobulin Y (IgY) with participation of microbial proteinases from Bacillus amyloliquefaciens (neutrase), B. thermoproteolyticus Rokko (thermolysin), Streptomyces griseus (pronase) and Aspergillus melleus. The progress of hydrolysis was monitored by the degree of hydrolysis (DH) and free amino groups concentration measurement. The resulting hydrolysates were subjected to an assessment of their ability to reduce the oxidation state of metal ions, scavenging of 2,2-di(4-tert-octylphenyl)-1-picrylhydrazyl (DPPH) free radicals and chelating iron ions.The highest degree of hydrolysis of both proteins was obtained during the reaction with proteinase from S. griseus. The highest level of reduction in the oxidation state of iron ions was observed in IgY 24-hour hydrolysates obtained with the participation of enzyme from B. thermoproteolyticus Rokko (409.7 μg Fe 2+ /mg). However, the 24-hour hydrolysates of IgY obtained after degradation with the proteinase from A. melleus, possessed the highest free radical scavenging activity equal to1.46 μM trolox/mg. The highest activity of chelating iron ions, equal to 891.64 µg Fe 2+ /mg, was observed for products obtained during the 24-hour hydrolysis of phosvitin with the participation of protease from B. thermoproteolyticus Rokko.

Egg Yolk as a New Source of Peptides with Antioxidant and Antimicrobial Properties

“…A remarkable outcome was attained through the implementation of a sequential two-step hydrolysis approach, comprising an initial 2 h papain hydrolysis, followed by a subsequent 2 h pepsin hydrolysis. Table 5 shows a comparison of the present results with those reported for a short digestion time (2–4 h) with such enzymes as neutrase, pronase, alcalase, or trypsin (25–33%) [ 33 , 37 , 43 , 44 ].…”

“…Our assumption was to create a mixture with antioxidant values in a simple way. Eckert et al [ 43 ] showed comparable results of the free radical scavenging ability of phosvitin (0.11 μM Trolox/mg) after 5 h hydrolysis with bacterial proteases. Graszkiewicz et al [ 45 ] demonstrated similar levels of free radical scavenging activity of egg protein hydrolysate (with trypsin) after separation on RP-HPLC.…”

Chicken Egg Proteins and Derived Peptides with Antioxidant Properties

“…Other enzymes from the microbial origin such as neutrase, thermolysin and pronase, among others, have also been used to produce hydrolysates with in vitro DPPH scavenging and chelating iron activity [77,93,94]. Sakanaka et al reported that egg yolk protein hydrolysates, obtained with the action of proteinase from Bacillus sp., display antioxidant activities in a linoleic acid oxidation system [77].…”

Biologically Active Peptides Released From Food Proteins

“…Liczba znanych sekwencji biologicznie aktywnych peptydów pochodzących z białek żywności zwięk-sza się. Do tej pory zidentyfikowano je we wszystkich surowcach białkowych wykorzystywanych do produkcji żywności oraz w wielu produktach spożywczych, głównie w mleku, fermentowanych produktach mleczarskich i serze [1, 49,56], surowcach i produktach roślinnych [48,81], mięsie [86], jajach [18,19,82] i rybach [93]. Biologicznie aktywne peptydy pochodzące z białek żywności zawierają 2 ÷ 20 reszt amino-kwasowych [49].…”