Biotransformation of bovine tannery fleshing into utilizable product with multifunctionalities

Leather industries aim at the transformation of putrescible animal raw hides and skins into a stable non-putrescible material (leather), ultimately resulting in solid wastes generation. Storage of limed bovine fleshing, a predominant proteinaceous solid waste material from pre-tanning processes is highly discouraged due to their putrescible nature. Diversely, bio-conversion of solid waste into a saleable product could be achieved by bacterial fermentation process. Lactic acid (LA) fermentation with Delimed Bovine Tannery Fleshing (DBTF) by Lactobacillus plantarum was experimented; incubation time, tapioca flour and lactose were the three prime independent variables studied. Maximum LA production in steam cooked DBTF medium was achieved with pH 6; inoculum 12.5% (v/w); lactose 8.81% (w/w) and tapioca flour 8.9% (w/w) at 96 hours of fermentation. Initial yield of about 4.56 g/L of LA (p < .05), upon statistical manipulation of the medium composition marked up to 12.36 g/L, enabling 2.7-fold increase in the LA production with DBTF as a relatively cut-rate substrate. Fermentation resulted in Fermented Fleshing Flour (FFF) with marked protein level of 76.32% and lower fibre content. Formation of protein hydrolysates and new acid groups in FFF were authenticated via Field Emission Scanning Electron Microscopic (FE-SEM) and Fourier Transform Infra-red Spectroscopic (FTIR) analyses respectively. In situ acid (LA) generation and formation of protein hydrolysates/free amino acids during LA fermentation points to the antibacterial (against Gram-negative bacteria, followed by Gram-positive bacteria) and in vitro antioxidative properties with dose dependency, of FFF, favouring its possible utilization in aqua feed industries as a superior grade proteinaceous feed ingredient with inbuilt bio-functionalities.”