Lemon verbena (Lippia citrodora) essential oil effects on antioxidant capacity and phytochemical content of raspberry (Rubus ulmifolius subsp. sanctus)

The aim of this study was to evaluate the effects of Lemon verbena essential oil on antioxidant and enzyme activity and phytochemical contents of raspberry. Lemon verbena essential oil at concentrations of 0, 250, 500, and 750 mu l l(-1) were used as a fruit edible coating with antioxidant and fungicide properties. The results showed that, in most parameters, there were statistically significant differences between the treatments and control fruits. The findings revealed that the antioxidant activity measured by DPPH method was increased in most treatments during storage and the maximum amount was found in the treated fruits with 500 mu l l(-1) EO after nine days (85.63%). Also, flavonoid compounds showed some changes similar to antioxidant activity and the maximum amount was 3.97 mg Qu ml l(-1)extract. The PAL enzyme activity in most of the essential oil concentrations had an upward trend and its activity level changed from 51.17 to 130.78 mu mol trans-cinnamic acid min(-1). Our results indicated that the use of essential oil coating was effective in enhancing phytochemical contents and to providing a longer storage life with acceptable external and internal qualities in raspberry fruit.