Oxidation of Potato Chips: Correlation of Sensory Evaluation and Chemiluminescence Measurementsof Oxidized Potato Chips

摘要

Lipid oxidation is a main factor reducing the sensory quality of food products. Rancid flavoursresulting from oxidative decay reactions are usually detected by sensory evaluation panels. A highlysensitive instrumental Chemiluminescence (CL) setup was compared to sensory evaluation using commercialpotato chips. The aim of the presented experiments is firstly the quantification of lipid oxidationin the sense of stability and state of degradation; secondly the comparison of the sensory results with CLdata was of interest.Several Tests have been performed with commercially available potato chips: 2 experimentalsets of CL and sensory panels were used to test the sample’s change initiated by day-light photooxidation.The potato chips long term behaviour against oxidation at storage condition was analysed in aparallel experimental set by weekly characterisation of the oxidation induction time and simple Arrheniusparameterization of the oxidation onset event. The results show a clear, but moderate decreasingtrend of the activation energy.Sensory evaluation experts detected significant difference (alpha = 0.05) for the chips exposed today-light for at least 6 days. Significant changes were detected with the CL method already after 1 dayby quantifying the state of degradation by total luminescence (TLI) intensity measurements and after 3days by the OIT measurements.The sensitivity of the CL method is very promising in comparison to the sensory evaluation testssince the oxidation may be noticed earlier and in a more objective way than the commonly used sensorypanels. Moreover the CL testing is less expensive in realisation since only one operator is required. Furtherinvestigations are now in progress were the real time oxidation of potato chips at normal ambientstorage condition is supervised with the CL method an parallel sensory evaluation tests.