Ferric chloride

Chitosan (CS), degree of deacetylation not less than 85% of high molecular weight, Aldrich. 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine-4′,4″-disulfonic acid sodium salt (Ferrozine) were bought from Sigma Chemicals. Maleic-and phthalic anhydride were bought from NICE laboratory reagents. Hydrogen peroxide (H 2 O 2 ) 30%, Loba chemie, India. EDTA, ferric chloride, and ferrous chloride were supplied from BDH. Potassium ferricyanide was supplied from Riedel laboratory reagents. Trichloroacetic acid and thiobarbituric acid were supplied from SUVCHEM laboratory chemicals. Other reagents and solvents were of analytical grade.
Chicken breasts were collected from a local poultry processing plant immediately after evisceration. Samples were transported to the laboratory in an ice box and stored at 4 °C for no longer than 2 h before use. Samples were separated from the bones and minced in an electrical mincer. Twenty gram samples were sealed in polyethylene bags after the addition of 0.1% of the tested antioxidants and put on the refrigerator (4 ± 1 °C) shelf until analysis.
Synthesis and characterization of Chitosan derivatives. N-maleoyl Chitosan (NMCS) and N-phthaloyl Chitosan (NPhCS) were synthesized and characterized in detail in a previous study by Abd El-Rehim et al. 9) The structure of CS, NMCS, and NPhCS was illustrated as shown in Fig. 1.

We purchased 2,2-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,4,6-tripyridyl-s-triazine, o-phthalaldehyde (OPA), trifluoroacetic acid (TFA), bromophenol blue (BPB), ferrozine, glacial acetic acid, and thiobarbituric acid from Sigma Aldrich (St. Louis, MO). Other chemicals, such as ferric chloride and sodium acetate, were procured from BDH Middle East (Dubai, United Arab Emirates). All reagents for electrophoresis were purchased from Bio-Rad (Richmond, CA).