Comparative study of polymers and total polar compounds as indicators of refined oil degradation during frying

Abstract

The aim of this work was to compare the frying stability of refined olive pomace oil alone and blended with refined coconut oil during 60 successive sessions. Frying experiments were carried out at 180 °C and samples were evaluated by high-performance size-exclusion chromatography (HPSEC), measuring the polymers and polar compounds formed. The tocopherol content was also analyzed. At the end of the frying process, the lowest content of polymeric compounds (PC) and total polar compounds (TPC) were detected for the blend of refined olive pomace oil-refined coconut oil (ROPO/RCO) with 13.20% and 25%, respectively, compared to refined olive pomace oil (ROPO) pure with 16.9% and 34.5%, respectively. Hence, the present study based on PC and TPC as best quality indicators of frying oil degradation indicated that the frying behavior of ROPO pure significantly improved by the blending application with RCO and showed a higher chemical stability.

Stability of Bioactive Compounds in Olive-Pomace Oil at Frying Temperature and Incorporation into Fried Foods

“…The scarce studies published so far on the changes of OPOs during heating or frying focused on the modifications produced in the glyceridic fraction, primarily triacylglycerols, and the products formed [ 7 , 8 , 9 ]. However, to our knowledge, no reports have been published on how frying conditions affect the naturally occurring bioactive compounds present in the minor, unsaponifiable fraction of OPOs.…”

Performance of Olive-Pomace Oils in Discontinuous and Continuous Frying. Comparative Behavior with Sunflower Oils and High-Oleic Sunflower Oils

“…In the same work, they studied changes of volatile profiles of olive-pomace oil at 180 and 220 °C for the first time, as well as in extra virgin olive oil and palm oil. Other publications on the use of olive-pomace oils in frying have focused on improving their stability by adding coconut oil [ 19 , 20 ], squalene [ 21 ] or olive leaf extracts [ 22 ].…”

Optimization of Total Polar Compounds Quantification in Frying Oils by Low-field Nuclear Magnetic Resonance

“…All of the degradation products, except for the components (unaltered triglycerides) eluted by the nonpolar eluant, were identified here as total polar compounds, 20 including polymeric triacylglycerols, oxidized-triacylglycerols, oxidizedmonoacylglycerols, diacylglycerols, monoacylglycerols and free fatty acids. 21 Combined sequence for frying oils. Inspired by the work of Rudi et al, 22 a combined sequence was designed to measure the combined relaxation signals of frying oils, as shown in Fig.…”