The purpose of this study was to explore the possibilities of improving chilling stress tolerance of eggplant seedlings through exogenous melatonin (MEL) application. Eggplant (Hadrian F1) seedlings were treated with various concentrations (0, 1, 5 or 25 μM) of MEL via soil drench after which they were subjected to chilling stress at 5°C/10°C (night/day) for 3 days. Following stress imposition, the efficacy of MEL applications on enhancing chilling stress tolerance was determined by several physical and physiological measurements and biochemical analyses. The results demonstrated that exogenous application of MEL alleviated the adverse effects of chilling stress in eggplant seedlings. Among the MEL concentrations tested, 5 µM was determined as the most effective concentration since antioxidant enzyme (CAT, POX and APOX) and photosynthetic activities increased while visual and membrane damage decreased in 5 µM MEL-treated seedlings. Also, these results are the first experimental evidence that exogenous application of MEL could improve chilling stress tolerance in eggplant, but further detailed studies are necessary to better understand the mechanism in acquiring chilling tolerance.

In this study, the effects of UV B (50 µW/cm2) radiation at 306 nm on oil-in-water emulsions (O/W) using canola oil, soybean oil and linoleic acid were investigated. The oxidation rates of emulsions incubated at pH 7.0 and 37°C in the presence and absence of Cu (II) ions were determined by using iron (III) thiocyanate and thiobarbituric acid methods for the determination of primary and secondary products, respectively. The UV B-induced oxidation rates followed the order LA / Cu (II) > LA > Canola Oil / Cu (II) > Canola Oil > Soybean Oil / Cu (II) > Soybean Oil for both crops. Simultaneously, structural studies were performed using gas chromatography mass spectrometry (GC-MS). It was found that 18-carbon polyunsaturated fatty acid (PUFA) and monounsaturated fatty acid (MUFA) contents have an important role in canola and soybean oil oxidation. The unsaturated fatty acid contents of small carbon numbers increased for each emulsion sample, while the oxidation of fatty acid changes did not follow a regular order.

Vegetable extract oils are now widely used in health, cosmetics and food fields. The oxidation rates of these industrial oils are closely related to their chemical composition. In this study, fatty acid contents of St. John’s Wort (Hypericum perforatum) oil and Nettle seed (Urtica dioica) oil were investigated by gas chromatography (GS-MS) and the effects on lipid peroxidation time were tried to be related. The peroxidation of oil emulsions was carried out at in a ventilated incubation environment 37°C and pH 7. Pseudo first order constants of primer oxidation products (hydroperoxides) were calculated by Fe (III) SCN method and they found for St. John’s Wort oil and Nettle seed oil, (2.05±0.23)×10-1 and (6.64±0.54)×10-1 hour-1,respectively. This study was conducted by showed that the oxidation rates of St. John’s Wort and Nettle seed oils are closely related to the chemical composition as well as the saturation ratings of fatty acids.