Accelerated extraction of the fat content in cheese using a focused microwave-assisted Soxhlet device

A fast method for hydrolysis and extraction of fat in cheese based on the u se of a Soxhlet extractor assisted by microwaves is proposed. The use of th is type of energy dramatically reduces the time required for both steps (na mely, the hydrolysis time was decreased from 1 h to 10 min with avoidance o f the neutralization step, and the extraction time was decreased from 6 h t o 40 min), providing similar efficiency and reproducibility comparable to o r better than that of the conventional Soxhlet methodology. In addition, th e proposed method is cleaner than conventional Soxhlet, as 80-85% of the ex tractant is recycled. The determination of the fatty acid composition by ga s-liquid chromatography and quantification of both polymer formation by hig h-performance size exclusion liquid chromatography and nonpolar triacylglyc erol formation by thin-layer chromatography with flame ionization detection in the extracts obtained by the proposed method, conventional Soxhlet and Weibull-Berntrop procedures (Soxhlet with a prior hydrolysis step), showed that the quality of the extracts obtained by the proposed procedure is bett er than that of the conventional alternatives, possibly due to the shorter time required by the accelerated method.