Physicochemical properties and formation process of micro-nanoparticles (MNPs) in pork bone soup under different stewing processing

Abstract

Pork bone soup, as a traditional worldwide dish, provides an alternative way for underutilized porcine bone. With the help of household pressure cookers, preparing soup has become much more convenient and accessible. Herein, this study investigated the physicochemical changes and formation process of micro-nanoparticles (MNPs) under different stewing conditions. Results showed that after 60 min of high-pressure and 60 min of normal-pressure stewing, spherical MNPs with 295 nm of particle size and −12.9 mV of zeta potential were found. FT-IR spectroscopy and content analysis confirmed the accelerated dissolution of proteins, triglycerides, and polysaccharides. Structural evaluations using SDS-PAGE and CD spectroscopy showed that collagen was denatured and broken down into gelatin, while surface hydrophobicity and fluorescence analysis highlighted more exposed hydrophobic group. Further enzymatic hydrolysis and confocal laser scanning microscope (CLSM) revealed that triglycerides were encapsulated by proteins through the hydrophobic interaction, and polysaccharides and/or glycoconjugates were located at the outer layer of MNPs. This study not only elucidates the process of MNP formation but also emphasizes the industrial potential of pork bone soup as a sustainable source of nutrient compounds, paving the way for advancements in food processing and nutrition science.