The mechanism of molecular cross-linking against nonenzymatic degradation in the body wall of ready-to-eat sea cucumber

Ready-to-eat sea cucumbers (RSC) treated by high pressure steam were easily degraded during storage. Celery (Apium graveolens, AG) and chlorogenic acid (CA) were screened for enhancing the stability of RSC. After RSC cross-linked by AG or CA, the hardness was significantly increased by 108% or 254% at 30 d, and the relaxation time decrease by 31.90 or 39.89 ms, and the proportion of T23 reduced by 0.40% or 1.15%. The crosslinked RSC exhibited smaller pore size with finer collagen fibrils. CA treatment caused the secondary structure changes in RSC. In addition, it also inhibited the break of peptide bonds in RSC collagen, observing the decrease of free hydroxyproline level from 46.63 to 34.53 μg/g, and the reduction of free ammonia nitrogen from 20.96 to 15.30 μmol/g. Therefore, AG and CA will have an important application in RSC processing industry.