Conformational Changes in Proteins Caused by High-Pressure Homogenization Promote Nanoparticle Formation in Natural Bone Aqueous Suspension

Abstract

As a natural calcium resource, animal bone needs to be miniaturized to the nanoscale to improve palatability and absorption capacity. To explore the mechanism of high-pressure homogenization (HPH) in preparing natural bone aqueous nanosuspensions, the relationships between the changes in protein conformation, solubility and quality characteristics of rabbit bone aqueous suspensions (RBAS) prepared by different HPH cycles were studied. The results showed that the improvements in particle size, stability and calcium solubility of RBASs could be mainly attributed to the improvement of protein solubility induced by the changes in protein conformation. HPH treatment led to the denaturation and degradation of protein in rabbit bone, generating soluble peptides and improving the stability of the suspensions by enhancing the surface charge of the particles. When collagen as the main protein was partially degraded, the hydroxyapatite in the bone was crushed into tiny particles. The increase in the particle-specific surface area led to the release of calcium ions, which chelated with the peptides to produce peptide calcium. However, excessive HPH treatment caused the production of protein macromolecular aggregates and affected the quality of RBASs. This study is helpful to promote the application of HPH technology in animal bone nanoprocessing.

Properties of Bovine Collagen as Influenced by High-Pressure Processing

“…Opposite this, Val and Ile are non-polar with long carbon chains; consequently, they are hydrophobic. UHP strongly modifies the structure of water, which allows exposure of the non-polar surface to water and eventually completely stops hydrophobic interactions resulting in the reorganization of amino acid residues in peptide chains [52]. SEM microscopy showed that 400 MPa for 10 min did not evoke significant changes in configuration and ordering over longer distances than the original collagenous gel.…”

“…The side chains of Glu and Asp have carboxylic acid groups whose pKas are low enough to lose protons, becoming negatively charged. Appropriate amounts of UHP cycling can disrupt hydrogen bonds, ionic bonds, and disulfide bonds [52]. Opposite this, Val and Ile are non-polar with long carbon chains; consequently, they are hydrophobic.…”

Tartary Buckwheat Starch Modified with Octenyl Succinic Anhydride for Stabilization of Pickering Nanoemulsions

“…High-pressure homogenization (HPH) is a non-thermal physical process for reducing the particle size of a sample (emulsion or suspension) from the micron range to the nanometer range by using shear, impact and cavitation effects at high pressure [ 22 ]. Due to its high production efficiency and stability, HPH has been widely used to produce emulsions [ 23 ], nanosuspensions [ 24 ], liposomes [ 25 ], etc. However, few studies have focused on the application of HPH to produce Pickering nanoemulsions.…”