Effect of ultra-high pressure treatment on biological macromolecules


(1) Ultrahigh pressure treatment and continuous pressure will destroy the microbial cell membrane; At the same time, ultra-high pressure treatment will destroy the biological macromolecules inside microorganisms. When the pressure is greater than 400, the inactivation rate of microorganisms increases with the increase of treatment pressure MPa When the inactivation rate of microorganisms reaches 99%, the increase is slow; At the same time, with the increase of holding time, the inactivation rate of microorganisms is also rising. When the pressure is greater than 20, the microbial inactivation rate reaches about 99% in min and rises slowly;

(2) The number of microorganisms increased with the number of days; When the treatment pressure is greater than or equal to 400 MPa or the pressure holding time is greater than or equal to 20 minutes, the number of microorganisms is 20 days, and there is no significant increase;

(3) After being processed by ultrahigh pressure food sterilization equipment, protein molecules will be depolymerized, exposing many hydrophobic groups, enhancing the hydrophilicity of protein molecules, and enhancing the solubility of protein in water; Ultrahigh pressure treatment exposes many hydrophobic groups, enhances solubility, exposes many hydrophobic groups, and enhances the viscosity, emulsification characteristics and surface hydrophobicity of proteins;

(4) Ultrahigh pressure treatment, 400Mpa protein molecules are completely denatured; Ultrahigh pressure treatment can change the second, third and fourth structures of protein molecules, but at 500MPa, the primary structure does not change;

(5) A lot of amylopectin is pressed into amylose with small molecular weight by ultra-high pressure treatment. Because starch granules are smaller and their specific surface area is increased, the probability of water molecules binding to free hydroxyl groups of starch is increased, the solubility and transparency of starch are significantly improved, and the viscosity of starch is reduced. At the same time, the improvement of starch rheological properties and structure also improves the starch pasting properties. The above ultra-high pressure treatment at 300MPa can make starch pasting and effectively reduce the starch pasting temperature;

(6) 500MPa When the structure of the unformed area changes, a lot of water enters these unformed areas; On the other hand, the expansion of water leads to the destruction of the crystalline regions connected with these regions. Through the experimental research in this paper, we not only have a very deep understanding of the changes in the physical and chemical properties of biological macromolecules in food under ultra-high pressure treatment, but also have a systematic understanding of the changes in the structure of biological macromolecules, providing a reference value for the ultra-high pressure food industry.

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