Surface stiffness and density of eggplant during storage Original Research Article

Changes in surface stiffness, mass, volume and density of fresh as well as stored eggplants were studied. Storage period was varied between 0 and 168 h at 15–30 °C temperature and 90% relative humidity. Mass and volume were measured using standard methods and density was computed from them. Surface stiffness was determined using force–deformation curve obtained on uniaxial compression testing machine. Surface stiffness and volume of eggplant decreased nonlinearly till certain time of storage whereas mass decreased linearly throughout the storage period; and the density showed a reverse trend. Rate of reduction of these properties was observed maximum at 25 °C storage temperature. The storage period of 96 and 120 h were found to be critical for the eggplant stored at 30 and 20–25 °C, respectively, after which it may start rotting and may not be good enough to use them for vegetable purposes. Eggplant stored at 15 °C did not show any such sign of detoriation in the ranges of variables studied.