Effects of Storage Conditions on Lycopene Stability in Tomato Extracts. An Undergraduate Experiment

Lycopene isomers can be isolated in samples of fresh tomato fruits, Lycopersicon esculentum L. Following homogenation the fruit tissue was extracted using organic solvents. Analysis of dried extracts was performed using high-performance liquid chromatography (HPLC) with photodiode array detection (PDA). Initial analysis indicated only one isomer of lycopene (all-trans-lycopene). However, when the extract was incubated at room temperature (25 °C) under ambient light conditions for seven days and analyzed again via HPLC, a more bioactive form of lycopene, the cis isomer, was present in both low- and high-oxygen environments. This procedure is inexpensive and scaled for classroom laboratory applications. It demonstrates the importance of sample preparation and storage conditions on compound stability.