Lipid droplet remodeling during salt curing-induced lipolysis in porcine muscle: Insights from lipidomics.

Lipid droplets (LDs) are the primary organelles responsible for storing neutral lipids. As a key factor in curing, salting has poorly understood effects on intramuscular LDs. In this study, porcine biceps femoris muscles were dry-salted with 1% or 3% NaCl for 3 d, and isolated LDs were subjected to lipidomic analysis (pooled samples). A total of 458 lipid molecules were identified, among which triacylglycerols (132, 28.82%), phosphatidylcholines (58, 12.66%), phosphatidylethanolamines (53, 11.57%), and diacylglycerols (37, 8.08%) were dominant. Multivariate analysis revealed separation among different groups, indicating salt-dependent remodeling of LD lipids. Phospholipid downregulation was extensive, coinciding with reduced LD particle size and suggested altered surface phospholipid composition. Core glycerolipids showed a shift in predominant triacylglycerol species from 56 carbons to 54 (1%) and 50 (3%), reflecting selective remodeling of TG molecular species under enhanced lipolytic conditions. This study provides a subcellular perspective for understanding salt-regulated lipid transformation in meat processing.