Figure 15 Detail of a chromatogram of a plant sterol ester mix, typically used in PS-enriched consumer products, after saponification. Shown is the elution window of the 4-desmethyl type of sterols. (Reprinted with permission from GSMJE Duchateau, CG Bauer-Plank, AJH Louter, M van der Ham, JA Boerma, JJM van Rooijen, PA Zandbelt. Fast and accurate method for total 4-desmethyl sterol(s) content in spreads, fat-blends, and raw materials. J Am Oil Chem Soc 79:273–278, 2002.)

doi:10.1201/9780203913413-24

Chapter

Figure 15 Detail of a chromatogram of a plant sterol ester mix, typically used in PS-enriched consumer products, after saponification. Shown is the elution window of the 4-desmethyl type of sterols. (Reprinted with permission from GSMJE Duchateau, CG Bauer-Plank, AJH Louter, M van der Ham, JA Boerma, JJM van Rooijen, PA Zandbelt. Fast and accurate method for total 4-desmethyl sterol(s) content in spreads, fat-blends, and raw materials. J Am Oil Chem Soc 79:273–278, 2002.)

Chapter

ABSTRACT

PSs are very stable molecules but may undergo oxidation due to the presence of a double bond in the B ring (46,50). In addition, side chain oxidation can occur due to enzymatic reactions or excessive heating (51). In order to assess the extent to which this occurred, an analytical procedure was developed for the determination of concentration levels and identity of polar PS oxidation products (PSOPs). Sterol oxidation products appear at trace levels, which implies the use of sensitive methods. Due to the similarities between the structures of the different sterol oxidation products, the applied analytical tool requires high resolution. Furthermore, interfering compounds from the food matrix can complicate the trace analysis of sterol oxidation products. Moreover, the instability of some sterol oxidation products and the possibility of further oxidation of the sterols during sample handling in the analytical procedure requires mild enrichment procedures and careful sample handling.