Unsaponifiables and phytosterols

Commercial com oil has been recognized as containing the highest levels of unsaponifiables (1.3-2.3%) of all the commercial vegetable oils (Strecker et al. 1996). The three main chemical components in the unsaponifiable fraction of com oil are phytosterols, tocopherols and squalene. 

Com germ oil contains two phytosterol lipid classes, free phytosterols and phytosterol fatty acyl esters (Table 10.1). Phytosterols have been recognized as one of the twelve most important classes of phytonutrients (Fahey et al. 1999). Most chemical identification of phytosterols in vegetable oils has been conducted by saponifying (hydrolyzing with base) the oil and measuring the resulting free phytosterols, usually by GLC (Table 10.4). The major phytosterols 

Oil Campesterol Stigmasterol (j-Sitosterol Sitostanol A5-Avenasterol A7-Stigmasterol A7-Avenasterol Reference 

Worthington and Hitchcock (1984) reported, on the basis of GC examination, that squalene was the major hydrocarbon in com germ oil and Moreau and coworkers (2000) recorded about 0.2% of squalene in both the fiber and the germ oils. 

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