Lífmassa

Lífmassa is a term used in Portuguese-language literature to denote the total lipid mass contained in a biological sample. It is a standard metric in lipidology and lipidomics for quantifying overall lipid content and enabling comparisons across tissues, treatments, or species. The value is typically expressed as milligrams of lipids per gram of tissue or as a proportion of the sample’s total mass.

Measurement of lífmassa generally involves extracting lipids with organic solvents, followed by weighing the lipid extract. The common Folch method uses chloroform–methanol, while the Bligh and Dyer procedure is another widely employed protocol. After extraction and solvent evaporation, the remaining lipid mass is measured gravimetrically. Alternative approaches include Soxhlet extraction or colorimetric assays for specific lipid classes (such as triglycerides). Advances in analysis also include nuclear magnetic resonance and mass spectrometry-based lipidomics to provide detailed profiles of lipid classes and species, in addition to bulk mass.

Applications of lífmassa span nutrition science, food and agricultural research, and biomedical fields. It is used to assess dietary fat content, determine oil content in seeds and fruits, and evaluate adiposity or metabolic conditions in organisms. In plant and animal studies, lífmassa serves as a rapid, bulk measure of lipid reserves or lipid-rich tissues, often complemented by more detailed lipid-class analyses.

Limitations include potential extraction inefficiencies and co-extraction of non-lipid substances, which can bias results. The method’s accuracy depends on the solvent system, sample type, and adherence to standardized protocols. Therefore, lífmassa is most informative when used alongside class-specific lipid analyses and appropriate controls.