Acoustic Cavitation Assisted Alkaline Hydrolysis of Wool Based Keratins To Produce Organic Amendment Fertilizers

Abstract

The purpose of this work was to understand the effect of the acoustic cavitation on the alkaline hydrolysis of wool and compare it with a conventional method of steam based alkaline hydrolysis. In acoustic cavitation assisted alkaline hydrolysis, the effect of concentration of solid (wool) and alkali on the properties of wool were also investigated. In conventional alkaline hydrolysis, the experiments were carried in a laboratory scale autoclave at temperature of 120 °C and pressure of 2 bar for 15 min. While acoustic cavitation assisted hydrolysis was carried out using the untreated and treated wool, hydrolyzed samples were characterized using FTIR, TGA and DSC to find out the extent of structural degradation occurring as a result of the treatment. It was observed that both the processes resulted in to a cleavage of disulfide bonds in wool, which cross-link the protein chains and are responsible for the higher stability and lower solubility of wool. However, the acoustic assisted alkaline hydrolysis is an environmentally friendly and less energy intensive process as it was performed at room temperature. The wool hydrolysates produced using acoustic assisted alkaline hydrolysis could find a potential application in agricultural fields such as fertilizer, soil improvement additive, etc.

Effective biodegradation of chicken feather waste by co-cultivation of keratinase producing strains

“…Chicken feathers are degraded mainly by physical methods (pressurized hydrolysis, and puffing) and chemical methods (acid and alkali) [11–13]. However, these methods have limitations such as high energy consumption during the production process and substantial of damage to the products [14]. In recent years, biotechnological methods have been used to degrade keratin.…”

Extraction of Keratin from Rabbit Hair by a Deep Eutectic Solvent and Its Characterization

“…As a high value-added and environmentally compatible substance, the extracted keratin is widely studied in biological materials [2], and has found its applications in many fields. The wool-based keratin hydrolyzates obtained by superheated water and alkaline hydrolysis, and with low molecular weight, were used as an amendment fertilizer to improve plant growth and soil condition [3,4]. The polypeptides of chicken feather keratin hydrolyzed by calcium hydroxide at a high temperature were used as an animal feed supplement [5].…”

Production of biologically active peptides by hydrolysis of whey protein isolates using hydrodynamic cavitation

“…These cavities produce high temperature and pressure states liberating a huge amount of energy in a due course of time [26] . The turbulence, shear stresses and collapse pressure in combination with the formed free radicals effectively breaks down the protein particles and facilitate the formation of WPI hydrolysates [11] , [14] .…”

“…Proteins can be efficiently hydrolyzed by acid, alkaline, thermal, and enzymatic treatment, either individually or in combination. Hydrolysis of proteins with acid and alkaline treatments have constraints of high amount of acid and alkali, complexities in handling due to high operating temperature and pressure, and need of their recovery [11] . Enzymatic hydrolysis is an environmental friendly approach, but it also has limitations of high processing cost and time of hydrolysis [12] .…”

“…The physical effect like turbulence is also produced after the liquid circulation [15] . Previously, different proteins such as keratin [11] , peanut milk protein [16] , and soy protein isolate [17] have been successfully degraded and/or hydrolyzed by the application of hydrodynamic cavitation under different set of optimized conditions.…”