Antioxidant capacity of hydrolyzed porcine tissues

The antioxidative capacity of seven different porcine tissue hydrolysates (colon, appendix, rectum, pancreas, heart, liver, and lung) were tested by four different assays, including iron chelation, 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging, 2,2-Diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl (DPPH) radical scavenging, and inhibition of lipid oxidation. All hydrolyzed tissues displayed antioxidant capacity in all four assays, with colon, liver, and appendix as the three most potent inhibitors of lipid oxidation (47, 29, and 27 mmol/L trolox equivalent antioxidant capacity [TEAC], respectively) and liver, colon, pancreas, and appendix as the four most potent iron chelators (92% ± 1.1, 79.3% ± 3.2, 77.1% ± 1.8, and 77% ± 2.3, respectively). Furthermore, colon and appendix showed good radical scavenging capacities with ABTS scavenging of 86.4% ± 2.1 and 84.4% ± 2.9 and DPPH scavenging of 17.6% ± 0.3 and 17.1% ± 0.2, respectively. Our results provide new knowledge about the antioxidant capacity of a variety of animal by-products, which can be transformed into antioxidant hydrolysates, thereby creating added value

Antioxidant capacity of hydrolyzed animal by-products and relation to amino acid composition and peptide size distribution

The antioxidative capacity of six different tissue hydrolysates (porcine colon, heart and neck and bovine lung, kidney and pancreas) were tested by three different assays monitoring iron chelation, ABTS radical scavenging and inhibition of lipid oxidation in emulsions, respectively. The hydrolysates were also investigated with respect to amino acid composition and peptide size distribution. The hydrolysates contained peptides ranging from 20 kDa to below 100 Da with a predominance of peptides with low molecular weight (53.8 to 89.0 % below 3 kDa). All hydrolysates exhibited antioxidant activity as assessed with all three methods; inhibition of lipid oxidation ranging from 72 to 88 % (at a final protein concentration of 7 mg/mL), iron chelation capacity from 23 to 63 % (at 1.1 mg/mL), and ABTS radical scavenging from 38 to 50 % (at 10 μg /mL). The antioxidant activity did not correlate with the proportion of low molecular weight peptides in the hydrolysed tissues, but with the content of specific amino acid residues. The ABTS radical scavenging capacity of the tissues was found to correlate with the content of Trp, Tyr, Met and Arg, whereas the ability to inhibit the oxidation of lineoleic acid correlated with the content of Glu and His. The chosen animal by-products thus represent a natural source of antioxidants with potential for food application