# Studying the Process of Enzyme Treatment on Beef Meat-Bone Paste Quality
There are two methods for destruction of the supramolecular structure of collagen with preservation of the structure and properties of tropocollagen--the enzymatic treatment and the alkaline salt treatment. Enzymatic treatment involves the use of enzymes, such as collagenase, which specifically target and break down collagen molecules. These enzymes hydrolyze peptide bonds within the tropocollagen structure, leading to the degradation of collagen fibrils and fibers. As a result, the strength of fibrils and fibers sharply decreases, and the subsequent action of the reagent provides collagen dissolution [12; 13; 14]. Enzymes are widely used in the food industry. Specialists and scientists have developed processes for separating meat from bones using proteases, as well as methods for splitting meat waste into fat, soluble protein, insoluble protein, and bone fractions using various enzymes [15]. In China, methods for processing meat-bone raw materials from the poultry processing industry for food purposes have been proposed [16; 17]. There are known studies on the use of ultrasonic pre-treatment to promote enzymatic extraction of chicken bone protein [18]. [PERSON] and others [19] proposed a method for acid treatment and extraction of collagen with pepsin from the waste of skin and bones of the golden pompano. Scientists from Indonesia studied the isolation of collagen from goat bone and determined its characteristics using enzymatic hydrolysis with pepsin at various concentrations [20]. The use of enzymes in meat processing plays a crucial role in enhancing both meat quality and processing efficiency. These enzymes, derived from microorganisms, plants, or animal tissues, are known for their ability to break down tough muscle fibers and connective tissues, thereby improving meat texture, juiciiness, and overall palatability. Commonly used enzymes, such as papain, trypsin, pepsin, ficin, and microbial proteases, are well-recognized for their ability to tenderize meat and facilitate processing [21]. Pepsin, one of the key enzymes mentioned, is a globular protein with a molecular weight of about 34,500 Da (daltons). The pepsin molecule is a polypeptide chain consisting of 340 amino acids and contains 3 disulfide bonds and a phosphoric acid group. Pepsin is an endopeptidase, an enzyme that cleaves central peptide bonds in protein and peptide molecules [22]. Its optimal catalytic activity is observed at a low pH range of approximately 1.5 to 2.0. The low pH is necessary for the activation of pepsinogen, the inactive precursor of pepsin, into its active form [23; 24]. Beyond its role in tenderizing meat, enzymatic processing holdspromise in the bioconversion of animal and poultry byproducts into value-added products. This approach not only enhances the nutritional value of byproducts but also contributes to environmental sustainability by reducing waste [25; 26]. The goal of this research was to study the effect of enzyme and organic acid treatment of meat-bone paste on the particle size, microstructure and physicochemical properties. Processing of meat-bone raw material into a fine paste allows the addition of this product to meat products (sausages, pates, cutlets, meatballs, etc.). Since the meat-bone paste is produced without heat treatment, it retains all the highly valuable vitamins, protein and mineral substances. The use of meat-bone paste for food purposes could solve the problem of insufficient supply of mineral and protein components to the human organism. Furthermore, the costs for producers of meat products may be significantly reduced.