Frying Performance of Canola Oil Triacylglycerides as Affected by Vegetable Oils Minor Components

Abstract

The endogenous minor components from canola, rice bran, sesame and palm oils including selected phospholipids, and various combinations of tocopherol isomers were tested during frying using canola oil triacylglycerols as the frying medium. Thermo-oxidative degradation was assessed by measurement of the total polar components, the rate of volatile carbonyl compounds and 4-hydroxynonenal formation. All the tested minor components protected to a different extent canola triacylglycerides from thermo-oxidative degradation during frying. No significant differences were observed in the protection of the triacylglycerides among all the tested tocopherol isomers and their mixtures. Irrespective of the composition of tocopherol homologous, an increase in the added amounts above 1,000 lg/g did not improve protection. Minor components isolated from rice bran and sesame oils offered better protection during canola triacylglycerides frying than endogenous minor components isolated from canola oil. When 0.2% phosphatidylcholine or phosphatidylethanolamine was added to the canola triacylglycerides, the amount of formed polar components decreased twice as compared to the tocopherol isomers. Accordingly, by optimizing the composition and the concentration of the endogenous minor components, the frying performance of oil can be significantly enhanced.

Stability and Antioxidant Activity of Annatto (Bixa orellana L.) Tocotrienols During Frying and in Fried Tortilla Chips

“…It appears that this level was sufficient such that the AnT3 did not provide any added benefit. This is supported by several studies in the literature that indicate that αT activity at frying temperatures is maximized at relatively low concentrations compared to γT and δT (Lampi and Kamal‐Eldin ; Romero and others ; Aladedunye and Przybylski ). Finally, in contradiction to the above‐mentioned studies showing that tocopherol mixtures had better antioxidant activity than single components, Aladedunye and Przybylski () reported no significant difference in the formation of PTAG and total polar compounds between a high oleic sunflower oil with αT (1110 μg/g) as the major T, and a high oleic sunflower oil that had instead a mixture of γT (361 μg/g) and δT (266 μg/g), although differences in the total T content may have influenced these results.…”

Perspectives on the use of seed oils in the South African diet

“…20 Furthermore, as lipid oxidation takes place primarily at the oil and air interface, oils should be stored closed in a cool, dark place as they may oxidise faster once opened. However, it should also be born in mind that seed and vegetable oils inherently contain antioxidants, most importantly tocopherols 32,33 and phenolic compounds, 22,34 which inhibit lipid oxidation and keep the oils stable during storage and heating. Currently, food scientists are also investigating the addition of natural antioxidants, such as rosemary extract, as well as using the biofilms of these antioxidants to create active packaging to prevent the lipid oxidation of oils and oil-containing foods.…”

“…21,40 The fatty acid composition of an oil, particularly the degree of unsaturation, further increases susceptibility to lipid oxidation. 20,32 Under frying conditions, even more so in shallow than deep frying, 41 a large number of volatile and non-volatile compounds are produced (conjugated dienes, peroxides, alcohols and carbonyls), of which a number exhibit carcinogenic, mutagenic and genotoxic properties. 42 The thermal stability of frying oils, which increases with the degree of saturation and antioxidant content, is another important criterion in the selection of a frying medium.…”

Used food oils: physical-chemical indicators of quality degradation

“…Lipid degradation induced by frying process and reuse or during long term or inadequate storage leading to oil rancidity, may occur by contacting (with prooxidants or rancid materials), chemical, enzymatic and microbiological pathways. Oxidation is probably the best known and studied process of degradation (Silva et al, 1998); it is a major economic concern of the industry, as it affects sensory (off flavours, browning, viscosity changes, foam) and nutritional quality of edible oils, with potentially toxic compounds formation (Aladedunye, Przybylski, 2011), like acrolein, ubiquitously present in cooked foods and environment (Moghe et al, 2015). In frying process, oil interacts with air, water and other food components, undergoing a complex chemical process of degradation by chain reactions, which affects the triacylglycerol molecules by hydrolysis and oxidation (Takeoka et al, 1997), the latter through a radical mechanism involving oxygen singlet ( 1 O), resulting into peroxidation (primary oxidation) and subsequently, fission, polymerization, condensation, interesterification, cyclization, etc.…”