Crude canolol and canola distillate extracts improve the stability of refined canola oil during deep‐fat frying

Abstract

Crude canolol (CAN) extracted from canola meal by accelerated solvent extraction and phenolic extracts from canola oil deodistillates (DDL) were assessed for their potential to stabilize canola oil during deep‐fat frying. Phenolics extracted from DDL with methanol ranged from 0 to 323 μg/g of DDL phenolics. French fries were deep fried in canola oil (3 L) enriched with 200 ppm of BHT, DDL, or CAN at 185 ± 5°C for 5 min. Twelve batches of fries (30 g each) were fried each day, 30 min apart for a total of 6 h of frying for 5 days. Both CAN and DDL extracts exhibited protection against frying oil deterioration compared to BHT with a considerable reduction in the hydroperoxides after the first day of frying. The ability to reduce primary oxidation was highest with CAN followed by DDL compared to BHT and the control (CAN>DD>Control). The total oxidation (TOTOX) and conjugated diene/triene values of oils fried with DDL and CAN were significantly (p<0.05) lower than BHT. Oil color correlated with AV (R2 = 0.822–0.985) in an exponential model with no major differences as compared to the control. In conclusion, based on the initial PV, TOTOX, and conjugated dienes, DDL and CAN both proved effective in inhibiting lipid oxidation during deep‐fat frying.Practical applications: Oil deodistillate is an excellent starting material for the production/recovery of a variety of bioactive components such as tocopherols, phenolics, phytosterols, or squalene. The present study confirms the beneficial effects of canolol and DDL phenolic extracts as antioxidants during the deep‐fat frying of canola oil. DDL is an abundant oil‐refining by‐product and this study demonstrates the value‐added potential of DDL as a crude source of phenolic antioxidants. This will provide new avenues for the value‐added opportunities due to their potent antioxidants. In contrast to the commonly applied synthetic antioxidants, the phenolic extracts tested in this study are part of endogenous oil components either removed from crude oil during refining (DDL) or produced during oil extraction process (canolol).Crude canolol and deodistillate (DDL) extracts protects canola oil from oxidative deterioration during deep‐frying at 185°C. The protective effect of crude DDL extracts and canolol extracts as indicated from the total oxidation (TOTOX) value of oils indicates potential for value‐addition of DDL.