In-vitro antioxidant and antibacterial properties of fermentatively and enzymatically prepared chicken liver protein hydrolysates

Protein hydrolysates were prepared from chicken
liver using fermentation and enzymatic hydrolysis. The lactic
acid bacteria Pediococcus acidilactici NCIM5368 was
employed in the fermentation process and a commercial protease
(Alcalase® 2.5) was used in enzymatic hydrolysis.
Chicken liver hydrolysates prepared by fermentation
(FCLH) and enzymatic hydrolysis (ECLH) revealed appreciable
amounts of protein [55.85 and 61.34 %; on dry weight
basis, respectively]. Fermentation and enzymatic hydrolysis
resulted in 14.3 and 26.12 % of degree of hydrolysis. Total
antioxidant activity, reducing power, scavenging of superoxide,
2- diphenyl-1-picrylhydrazyl (DPPH) and 2, 2-azino-bis-
3-ethyl-benzthiazoline-6-sulphonic acid (ABTS) radicals
were determined for both FCLH & ECLH. FCLH & ECLH
showed total antioxidant activity of 0.99 and 1.13 μg AAE
mg−1 proteins, respectively; while, they scavenged 96.14 and
92.76 % of DPPH radicals respectively. FCLH showed higher
ABTS radical scavenging activity (32.16 %) than ECLH
(19.29 %). Superoxide anion scavenging activity of FCLH
& ECLH were found to be 95.02 & 88.94 %, respectively.
Residues obtained after both treatments also exhibited antioxidant
activities. FCLH reported highest antagonistic activity
against Listeria monocytogenes (30 mm); while, ECLH
showed antibacterial activity only against Micrococcus luteus
(12 mm). Both hydrolysates have the potential to be a protein
rich ingredient for use in formulated foods and possible help
in reduction of oxidative stress.