Box-behnken design for the optimization using solvent-free microwave gravity extraction of garlic oil from Allium sativum L.

Garlic (Allium sativum L.) has compounds that could be used as anti-microbial, anti-atheroschlerosis, anti-oxidant, anti-viral, anti-cholesterol, anti-diabetic, anti-hypertension, and anti-cancer. In this paper, oils were extracted from garlic using Solvent-Free Microwave Extraction (SFME) method without solvent which is as an alternative technique to produce oil and it has several advantages in terms of product quality and quantity. This research used technique of gravity for extraction process and produce high yield of garlic oil. The highest results were obtained from this study when at 100 g, 450 W, 10 min, and 0.5 cm. Response surface methodology was designed to evaluate the effects of mass of raw material (g), microwave power (W), extraction time (min) and material size (cm) for optimization of analytical methods. Regression models have designed and predicted experimental values well. Gas chromatography-mass spectrometry (GC-MS) technology was used to analyze the chemical compositions of garlic oil. The results showed that sulphide compounds, like diallyl disulphide, trimethylene trisulfide, ester and alcohol which is found in garlic oil.