Irradiation with microwave energy has allowed to carry out the extraction of lipids from milk samples (namely, cow, goat and sheep) with quantitative results similar to the Weibull–Berntrop extraction procedure but milk fat obtained by microwave assisted extraction undergoes lesser chemical transformation of triglycerides during the whole process. A considerable reduction of the procedure time (50 min versus 10 h) is achieved with similar reproducibility to that provided by the conventional method. An `in situ’ solvent recycling step makes the method environmentally clean.

Spain's Comisión Interministerial de Ciencia y Tecnologı́a (CICyT) is gratefully acknowledged for financial support (Project PB96-0505).