Impact of Natural Antioxidants on the Chemical Stability of Corn Oil During Deep Frying.

内容摘要

Reusing frying oils increases the level of oxidation products while decreasing the healthiness and quality of the frying oils. One way to improve the oxidative stability of frying oils is to use them in combination with oils rich in natural antioxidants. The aim of this study was to evaluate how enriching refined corn oil with antioxidant-rich oils affected the corn oil's behavior during deep frying over an extended period. Refined Corn Oil (COO) was blended with Black Seed Oil (BSO), Blackberry Oil (BBO), Sesame Oil (SSO), Extra Virgin Olive Oil (EVOO), and Pomegranate Oil (PMO) in a proportion of 85:15 (v/v) to obtain five blends (COO/BSO, COO/BBO, COO/SSO, COO/EVOO, COO/PMO). Each oil was used to deep-fry falafel (frying temperature: 175 ± 5 °C for 20 minutes per cycle, 36 cycles) over 12 hours. Acid Value (AV), Peroxide Value (PV), p-Anisidine Value (p-AV), total oxidation value (TOTOX), Free Fatty Acids (FFA), Fatty Acid Profile (FAP), Total Polar Compounds (TPC), and viscosity were determined. The samples were collected after the last frying cycle and stored at -20 °C until analysis. All oil blends had significantly lower values of oxidation indicators (PV, p-AV, TOTOX), FFA, and TPC than corn oil. The most significant reductions in oxidation values, TPC, and FFA were observed in the olive, pomegranate, and sesame oil blends. Based on TOTOX values, oliveand pomegranate-based blends showed the highest oxidative resistance. Deep frying reduced C18:2 and C18:3 and increased trans-C18:1 in all studied samples. The least degradation of FAP was found in the olive and pomegranate blends. Enrichment of corn oil with naturally antioxidant-rich oils may slow oxidative processes during deep frying and reduce the degradation of polyunsaturated fatty acids. The highest protective effect was observed for the pomegranate and extra virgin olive oil blends. Enrichment of corn oil with pomegranate or extra virgin olive oil significantly improved its oxidative stability during deep frying.