In vitro Antioxidant and Antibacterial Properties of Hydrolysed Proteins of Delimed Tannery Fleshings: Comparison of Acid Hydrolysis and Fermentation Methods

Proteins in delimed tannery fleshings were
fermentatively hydrolysed using Enterococcus faecium
NCIM5335 and also hydrolysed using mild
organic acids (formic acid and propionic acid). The
liquor portion containing hydrolysed proteins was
spray dried, in both the cases, to obtain a powder. The
spray dried powder was evaluated for in vitro antioxidant
activities with respect to scavenging different
free radicals and antibacterial properties against nine
different pathogens. Fermentation and acid hydrolysates
scavenged 83 and 75.3% of 2,2-azino-bis-3-
ethyl-benzthiazoline-6-sulphonic acid (ABTS) radicals,
respectively, at a protein concentration of 0.25 mg.
Further, fermentation hydrolysate showed higher 2,2-
diphenyl-1-picrylhydrazyl radical scavenging activity
of 59% as compared to 56% scavenging by acid
hydrolysate at a protein concentration of 5 mg. Acid
hydrolysate exhibited lesser (82.3%) peroxy radical
scavenging compared to hydrolysate from fermentation
(88.2%) at a protein concentration of 10 mg.
However, acid hydrolysate exhibited higher (89.2%)
superoxide anion scavenging while its fermentation
counterpart showed lower activity (85.4%) at 2.5 mg
hydrolysate protein. Well as superoxide anion
scavenging properties. All the in vitro antioxidant
properties exhibited dose dependency. Fermentation
hydrolysate exhibited maximum antagonistic activity
against Salmonella typhi FB231, from among host of
pathogens evaluated. Both the hydrolysates have
potential to be ingredients in animal feeds and can
help reduce oxidative stress in the animals.