Evaluation of SafTestTM methods for monitoring frying oil quality

The feasibility of applying methods developed by Safety Associates, Inc., to monitor oil degradation products, including malondialdehydes (AldeSafe^TM), FFA (FASafe^TM), and peroxides (PeroxySafe^TM), in fresh and heat-abused deep-fat frying oil was evaluated. Based on performance qualification studies, the AldeSafe method was the most suitable SafTest^TM assay for monitoring the quality of frying oil because of its high accuracy, precision, linearity, and reproducibility, and low detection/quantitation limits. A strong correlation (r=0.924) between the AldeSafe method and its counterpart, AOCS Official Method Cd 19-90, also supported the suitability of the SafTest method for monitoring oil quality. Moreover, the FASafe method had a moderately strong relationship with AOCS Official Method Ca 5a-40 (r=0.761). Our studies suggest that this test can be applied for monitoring frying oil; however, certain method performance limitations must be considered for routine analysis purposes. In contrast, the PeroxySafe method probably should not be used to monitor heat-abused oil without further development because of high variability, low accuracy, and low correlation (r=0.062) with the AOCS Official Method Cd 8-53 assay.