Abstract:

Volatile oil was obtained from crushed, peeled garlic cloves by the following steps: soaking in hot water, ultrasonic treatment and steam distillation. Single-factor experiments were conducted to evaluate the effects of four crucial factors, such as soaking temperature and time, material/water ratio, and distillation time on extraction yield of volatile oil. Subsequently, the four factors were optimized using an orthogonal array design involving 9 experiments. The most important affecting factor was distillation time, followed in turn by material/water ratio, and soaking temperature and time. A maximum extraction yield of volatile oil of 0.35% was obtained under the optimized conditions: soaking for 4 h at 35 ℃ with a material/water ratio of 1:3.5 prior to 2 h steam distillation. In general, the method is simple and practicable.

Key words: garlic, volatile oil, orthogonal test, extraction technology