Biotransformation of bovine tannery fleshing into utilizable product with multifunctionalities
Basheer Thazeem, Mridul Umesh, Vellingiri Manon Mani, Goldy Primo Beryl, Preethi Kathirvel
Abstract
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.”