It is known that in world practice today there are two well-known methods of extracting oil from oleaginous material: pressing - mechanical squeezing of oil using a press and extraction - extraction of oil from the material with a solvent.
the pressing method is more environmentally friendly and fireproof, unlike extraction, and also allows preserving valuable natural components in the resulting oils (especially by cold pressing). However, the pressing method does not allow for complete extraction of oil from the oilseed material, and a significant percentage of oil content always remains. That is why it is important to search for technologies that would intensify the process of pressing oil extraction, but would not lead to a deterioration in its quality. Among such technologies, the treatment of oilseeds before pressing with hydrolytic enzymes with proteolytic, cellulolytic, hemicellulolytic and pectolytic activity is promising, which can not only increase the yield of oil, but also increase its nutritional value by increasing the transfer of biologically active substances of oilseeds, in particular, such as tocopherols and phytosterols, to oil.
The practical significance of the results obtained for the oil and fat industry is to develop a technology for processing pumpkin seed flakes with mixtures of enzyme preparations with proteolytic, cellulolytic, hemicellulolytic, and pectolytic activity to increase the efficiency of pressing oil extraction.
It is known that oil in seed cells is contained in the form of lipid bodies (oleosomes), the shell of which is formed by complex protein compounds and phospholipids. At the same time, the oleosomes are protected from the outside by the pectin and lignocellulose matrix of the seed cell walls. Lipid bodies in seed cells are "woven" into the cytoplasmic membrane, which consists of proteins. The cell walls themselves consist mainly of lignin and polysaccharides such as cellulose, hemicellulose, and pectin, but also contain a significant amount of hydroxyproline-rich glycoproteins and complexes of arabinogalactans with proteins. The destruction of such membranes requires significant energy expenditure, and therefore, mechanical and physical forces alone are not sufficient to fully extract oil from the material. Hydrolytic enzymes are powerful catalysts for biochemical reactions of the breakdown of various complex organic compounds. In particular, drugs with proteolytic activity cause the breakdown of protein compounds and lipoprotein complexes, which are structural components of cell membranes and oil body membranes. At the same time, preparations with cellulolytic, hemicellulolytic and pectolytic activity catalyze the destruction of their corresponding polysaccharides, which are structural components of oilseed cell walls. In addition, enzymatic hydrolysis destroys complex compounds of tocopherols and phytosterols with seed polysaccharides, which causes the penetration of these biologically valuable compounds into the oil phase. Thus, the treatment of pumpkin seeds with hydrolytic enzymes in combination with traditional pressing technology can intensify the action of mechanical and physical forces aimed at maximizing the destruction of the structural components of the material and the release of oil from it, as well as increase the biological value and antioxidant properties of the resulting oil by increasing the content of tocopherols and phytosterols.
The working hypothesis of the dissertation is that the use of enzymatic treatment of oilseeds before pressing will increase the oil yield due to the intensification of enzyme destruction of the cellular structure of the oilseed material. Based on this, the main objectives of the work are to study the effect of proteolytic, cellulolytic, hemicellulolytic and pectolytic enzymes on the cell structure of pumpkin seeds, to select optimal parameters of enzymatic pretreatment of pumpkin seeds, to determine the effect of the technology on the quality, composition and antioxidant properties of the resulting oil.
Experimental studies in the laboratory have confirmed the proposed hypothesis that enzymes can achieve a higher degree of destruction of the cellular structure of the oil material and release more oil than traditional methods of oil extraction, without causing deterioration in oil quality and loss of biologically valuable components, and at the same time improving its antioxidant properties.
Based on the analysis of scientific and technical literature, experimental studies, mathematical modeling, and theoretical generalizations of the results obtained, a specific scientific task was performed to improve the technology of pressing oil extraction from pumpkin seeds using biotechnological methods.
Keywords: antioxidant properties, pumpkin seeds, pumpkin seed oil, hydrolytic enzymes, "destroyed" cells, enzymatic pretreatment, pressing.
