51B-3

B. INNAWONG and P. Mallikarjunan. Biological System Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061

The applications of chemosensory systems evaluating volatile compounds are currently being introduced in the food industries for quality control, process monitoring, and odor quality evaluation. There exists an interest in determining the possibility of using a chemosensory system instead of chemical analyses to investigate odor and volatile compounds in fried food products and frying oil.

This study was conducted to determine the possibility of using a chemosensory system to differentiate among varying intensities of oil rancidity and investigate discrimination between good, marginal and unacceptable frying oils.

Fresh, 1-day, 2-day used and discarded frying oils were obtained from a fast food restaurant in each frying cycle for 4 weeks. The oil samples were kept at 4 oC and analyzed using a chemosensory system. The discrimination between good, marginal and unacceptable frying oils with regard to rancidity was examined and the results were compared to chemical properties such as dielectric constant, P-value, and free fatty acid content.

The different qualities of frying oils were successfully evaluated using the chemosensory system. Good Discrimination and stability were obtained for identification between acceptable and unacceptable qualities of frying oil. According to chemical analyses, dielectric constant , P-value, and free fatty acid content of oil samples significantly increased (P<0.05) with the frying time. Good correlations were found between chemical analyses and chemosensory system responses.

Using chemosensory system to determine the frying oil quality is an alternative option for fried food industry to monitor and control the frying process because of its reliability, convenience and speed.