Other authors slightly modified this method introducing a solid phase extraction prepurification with silica before HPLC analysis (Rovira, Ribera, Sanchis, & Canela, 1993). These procedures are fast and inexpensive, however they may destroy patulin, whose lactone structure is not stable at basic working pH. In addition, these protocols have some problems with no clarified juice or complex matrixes such as baby food or mousse. MacDonald, Long, Gilbert, and Felgueiras (2000) suggest to use an enzymatic approach. Pectinase removes pectines from juice before HPLC analysis, and the digested solution is easier to analyze because a large part of interferences is eliminated from solution. This extraction and prepurification procedure requires at least 2 h at 40 C or incubation overnight at room temperature.