 22 oils and fats samples showed a huge diversity in composition  Oils and fats were grouped in 3 differentiated clusters by PCA  TPC and SFA correlate positively with IP  UFA, PUFA and total tocopherols correlate negatively with IP  SFA, MUFA and PUFA account for 67% of variability of IP ABSTRACT A detailed composition analysis was performed for 22 diverse oils and fats and included determination of tocopherols (α, γ and δ), β-carotene, chlorophyll, total phenolic compounds (TPC) and fatty acid (FA) composition, as well as the determination of their oxidative stability (Rancimat test). Principal components analysis was applied to obtain an overview of the sample variations and to identify

Lipid oxidation has been identified as the major deterioration process of vegetable oils. Undesirable effects are even more profound when food processing involves high temperatures in the presence of oxygen. Natural ground herbs (black pepper, ginger, turmeric, rosemary and oregano) were assessed for their antioxidant capacity, phenolic content and ability to improve the oxidative stability of vegetable oils. The most potent herb was incorporated in vegetable oils formulations which were subjected to consecutive frying cycles. The oxidative stability of the vegetable oils, the formation of conjugated dienes/trienes and the decimation of tocopherol levels after the frying process were assessed. Rosemary powder was the most effective antioxidant among the ones tested. The oxidative stability of tocopherol-stripped corn oil with rosemary powder (1.53 AE 0.06 h) was significantly higher than the control (0.84 AE 0.02 h) and the oil with synthetic antioxidants (1.20 AE 0.03 h). Rosemary powder effectively improved the oxidative stability of sunflower (128.91%), olive (55.61%) and rapeseed (73.20%) oil during deep-frying and prevented CD and CT formation in rapeseed oil.The frying process was carried out on commercially available oils namely olive, sunflower and rapeseed oil. Rosemary powder (0.5% w/v) was allowed to mix for

Summary Rapeseed oil is an important source of edible oil for the human diet but is also highly susceptible to oxidative deterioration. Previous research has demonstrated that rosemary powder and its extracts can increase the oxidative stability of rapeseed oil. In this study, the protective effect of ground rosemary powder (0.25–2.0%) against the oxidative degradation of filtered rapeseed oil was assessed. Rapeseed oil filtrate showed enhanced antioxidant capacity and higher induction periods (IP) based on Rancimat analysis. Lower conductivity changes and total colour differences, reduced malondialdehyde and conjugated dienes content, and higher levels of tocopherols and carotenoids were observed for the oils formulated with rosemary powder after 1.5 and 3 h of exposure to accelerated oxidation. The use of rosemary powder filtrate could be an effective way to protect rapeseed oil from oxidation during storage or cooking with domestic and commercial applications.