Mechanisms underlying the influence of “roe rubbing” and “salt mixing” on the qualitative transformation of fish roe into caviar: focusing on membrane phospholipids and proteins

This novel study explored how “roe rubbing” and “salt mixing” qualitatively transform fish roe into caviar, focusing on membrane phospholipids (PLs) and proteins. Salt mixing increased phosphatidylcholine (PC) concentration in membrane PLs, while DHA, linolenic acid, and linoleic acid levels decreased. After roe rubbing and salt mixing, Raman spectra of membrane PLs decreased at 1300, 1450, and 1655 cm −1 , indicating decreased torsional freedom of motion and C C telescopic vibration intensity. The hydrophobic environment formed by salt and interchain repulsion led to hydrogen bonding network, causing conformational changes in membrane proteins and increases in α-helix, β-sheet composition. Roe rubbing induced temporary disruption of protein chemical bonds, while eliminating contaminants mitigated off-flavors and improved the tissue condition. Salt caused osmotic pressure to release more lipids, which increased membrane thickness and consistent internal pore size, giving caviar elasticity and fullness. This work enhanced theoretical direction for caviar processing quality.