Effect of Essential Oil from the Leaves of Rosemary Used in the Control of Callosobruchus maculatus (F.) on the Hydration Coefficient, Cookability, Taste and Color of the Edible Chickpea

Loses caused by larvae of Callosobruchus maculatus (Fabricius, 1775) in stored legumes are significant. In this study, fumigant toxicity of Rosmarinus officinalis L. essential oil on 3 day-old eggs and mature larvae of C. maculatus, and, also its vapor effects on the hydration coefficient, cookability, color and taste of chickpeas were investigated. Trials were carried out at 28 +/- 2 degrees C temperature, 55 +/- 5 % relative humudity and 0/24 L/D periods in climatic cabinet. The main components of rosemary essential oil were determined as borneol (25.67 %), verbenone (23.55 %), camphor (20.48 %), 1,8-cineol (5.76 %) and alpha-terpineol (5.61 %). The highest egg mortality rates were found as 71 % at 24(th) and 100 % at 48(th) hour for 50 mu l L-1 air doses. Larvae mortality rates were determined as 87 % and 100 % at the 24(th) and 72(nd) hour in the most effective dose (50 mu l L-1 air) of rosemary essential oil, respectively. The highest dose (60 mu l L (-1) air ) and the longest exposure time (48 hours) of the essential oil did not show a negative effect on the hydration coefficient, cookability and color of chickpeas. However, the taste of the chickpea changed in ratio of 40 % at 10 mu l L-1 air dose and 24 hour exposure time. Essential oil vapor of R. officinalis showed fumigant effect on C. maculatus but distinct taste was determined on chickpeas. If the taste of rosemary essential oil vapor is removed from the chickpea, rosemary essential oil can be considered as a potential bio-fumigant in control of C. maculatus.