Effect of processing on oxidative stability and lipid classes of sesame oil

Sesame oil and seed products are highly stable against oxidative processes. The effects of sesame seed pretreatment, including roasting (R), steaming (S), roasting plus steaming (RS) and microwaving (M) on crude oil quality f rom intact Egyptian and Sudanese seeds were investigated. Oxidative stabili ty of seasame seeds was determined by monitoring changes in peroxide value (PV) and para-anisidine value (p-AV). The oils from RW and RS seeds showed higher oxidative stability than other processed oils. In addition, differen t lipid classes and subclasses present and their fatty acid composition wou ld influence the oxidative status of the oil. Neutral lipids constituted ab out 91.0% whereas monoglycolipids and diglycolipids each respresented 2.4 a nd 3.5%, respectively, and finally phospholipids represented 3.0% of the to tal lipids. Moreover, different processing treatments show considerable eff ects on lipid fractions. The influence on all components after RS was more pronounced than M treatment. (C) 2000 Elsevier Science Ltd. All rights rese rved.