Optimization of Microbial Hydrolysis Parameters of Poultry By-Products Using Probiotic Microorganisms to Obtain Protein Hydrolysates

Abstract

In connection with the active growth of poultry processing, the issue of rational use of poultry by-products is urgent. The paper proposes hydrolysis of the gizzards of broiler chickens and hens of the parent stock with bifidobacteria liquid concentrate (BLC) and Propionix liquid concentrated starter culture (Propionix LCSC). The effect of enzymatic treatment on changes in the structural components of the gizzards was studied using scanning electron microscopy (SEM) and determination of the dispersed composition. As a result of the research, the multiple regression equations and the response surfaces were obtained, which describe the optimal parameters of the gizzard´s hydrolysis process. The temperature and the time of hydrolysis are factors that have a significant effect on the degree of hydrolysis. The results of the structural and microscopic analysis confirm the high hydrolysability of the by-products by changing its structure and increasing the number of smaller protein particles. It was found experimentally that the gizzards of hens are more susceptible to the action of probiotic microorganisms’ enzymes compared to the gizzards of broiler chickens.

Physicochemical, Functional, and Technological Properties of Protein Hydrolysates Obtained by Microbial Fermentation of Broiler Chicken Gizzards

“…The data obtained is consistent with the results of a previous study which found an increase in the content of free amino acids and the dispersion of hydrolysates during fermentation by microorganisms [26,30]. The presence of peptides with low-molecular weight in protein hydrolysates contributes to increases in water-holding and fat-holding capacities.…”

“…Based on the results of previous studies and the optimal parameters of hydrolysis [26], the protein hydrolysate from the broiler chicken gizzards was obtained by means of microbial fermentation based on the technological scheme presented in Figure 1.…”

“…The total nitrogen content was assayed by the Kjeldahl method with nitrogen converted to equivalent pro- The key stages of the production process were washing, grinding, and degreasing the stomachs, the actual stage of fermenting with a bacterial concentrate, and the final processing of the resulting protein component. Fermentation was carried out under the following parameters determined in previous studies: temperature, 39-40 • C; hydrolysis time, 9-12 h; concentration of the bacterial concentrate in the substrate, 10-12% [26]. The degree of hydrolysis was 63.9% when treated with Propionix LCSC and 56.4% when treated with BLC.…”

Effect of Microbial Enzymes on the Changes in the Composition and Microstructure of Hydrolysates from Poultry By-Products

“…By-product homogenates without added bacterial concentrates were taken as controls. All homogenates were fermented at 37 • C for 24 h. Optimization of the hydrolysis process is given in an earlier work [21].…”

Effect of Fine Grinding Process on Temperature Characteristics and Water-Binding Capacity of Chicken Bone Paste

“…Chicken processing generates a very large amount of waste, some of which contains a large amount of nutritional components. One such waste is chicken bone, which is largely unused or limited in the production of animal feed, pet food and fertilizer [9,10]. Chicken bones are not used properly despite their high nutritional value and protein content.…”