Targeted free amino acid, nucleotide, and untargeted lipidomic profiling reveal tissue‐specific chemical composition and nutritional heterogeneity in Manila clam
Zheng Zhou, Meng Dong, Yu‐Ying Zhang, Xu‐Hui Huang, Lei QinAbstract
BACKGROUND
The Manila clam is a highly nutritious and sought‐after shellfish; however, a lack of detailed knowledge regarding tissue‐specific chemical composition hinders precision processing and contributes to waste. This study used targeted metabolomics and untargeted lipidomics to investigate the variations in free amino acids (FAA), 5′‐nucleotides, and lipid molecules in different tissues in the Manila clam.
RESULTS
Glycine, alanine, arginine, and glutamic acid were the most abundant FAAs, with higher concentrations detected in the foot, visceral mass, and siphon than in the adductor muscle and mantle. Sweet amino acids constituted 55.63% of the total FAAs, accumulating predominantly in the siphon, foot, and visceral mass. The highest accumulation of 5′‐nucleotides occurred in the foot. In total, 221 lipid molecules were annotated, comprising 44 triglycerides, 40 fatty acids, 25 ceramides, and various phospholipids. Among the five tissues, the visceral mass possessed the highest levels of triglycerides, ether lysophosphatidylethanolamines, and polyunsaturated lipids. Conversely, phospholipids – including the bioactive ether phosphatidylethanolamine – were more abundant in the adductor muscle, mantle, and siphon, peaking sharply in the adductor muscle.
CONCLUSION
Each tissue exhibits a distinct nutritional and chemical profile, indicating its potential for differentiated, high‐value utilization. The foot represents a viable source for umami flavorings or muscle‐based products, and the visceral mass shows promise as a raw material for functional oils. The siphon offers pathways for developing low‐sugar and thermally processed products, whereas the adductor muscle could be targeted for functional foods. These compositional insights establish processing directions, but further sensory and processing studies remain essential to validate practical applications. This study provides a scientific foundation for the precision utilization of Manila clam resources. © 2026 Society of Chemical Industry.