Determination of volatile profile of citrus fruit by HS-SPME/GC-MS with oxidized NiTi fibers using two temperatures in the same extraction procedure

摘要

This paper reports the preparation of fibers for solid phase microextraction by oxidized nitinol (NiTi) rods through contact with a boiling solution of H_2O_2. Also, a new optimization approach is described for the extraction of the volatile fraction of citrus juice based on the use of two extraction temperatures in the same HS-SPME procedure. A central composite design was performed by varying the extraction temperature from 5 to 50°C and the extraction time from 20 to 80min. The extracted compounds were divided into two groups (GR1 and GR2). Response surfaces were constructed, allowing the establishment of compromise conditions under which the temperatures could achieve a much better extraction and allow the identification of more volatile (GR1) and semi-volatile compounds (GR2). The optimized extraction conditions were obtained for a total extraction time of 40min, comprising 24min at 60°C and 16min at 5°C.