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

摘要

Lipid oxidation is a main factor reducing the sensory quality of food products. Rancid flavours resulting from oxidative decay reactions are usually detected by sensory evaluation panels. A highly sensitive instrumental Chemiluminescence (CL) setup was compared to sensory evaluation using commercial potato chips. The aim of the presented experiments is firstly the quantification of lipid oxidation in the sense of stability and state of degradation; secondly the comparison of the sensory results with CL data was of interest. Several Tests have been performed with commercially available potato chips: 2 experimental sets 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 a parallel experimental set by weekly characterisation of the oxidation induction time and simple Arrhenius parameterization of the oxidation onset event. The results show a clear, but moderate decreasing trend of the activation energy. Sensory evaluation experts detected significant difference (alpha = 0.05) for the chips exposed to day-light for at least 6 days. Significant changes were detected with the CL method already after 1 day by quantifying the state of degradation by total luminescence (TLI) intensity measurements and after 3 days by the OIT measurements. The sensitivity of the CL method is very promising in comparison to the sensory evaluation tests since the oxidation may be noticed earlier and in a more objective way than the commonly used sensory panels. Moreover the CL testing is less expensive in realisation since only one operator is required. Further investigations are now in progress were the real time oxidation of potato chips at normal ambient storage condition is supervised with the CL method an parallel sensory evaluation tests.