新鲜香葱油的提取工艺研究

采用微波-低温溶剂法，选择不同极性的溶剂，提取新鲜香葱中的芳香及呈味成分，所得葱油色泽碧绿，气味及滋味均呈鲜葱特征。最佳提取工艺为：在微波功率200W、温度45℃，液固比2:1，提取时间5min的条件下提取3次；第一次的溶剂为色拉油，提取液离心分离；第二、三次为丙酮-石油醚(1:1)，提取液合并后分液、浓缩；三次提取处理后的混合物即为香葱油。实验发现：葱油的新鲜程度与其色度变化间存在相关性，据此设计了葱油的储藏及检测方法。在不同温度 (30、5、－7、－17℃)条件下保存30d后，通过分光光度法测定相应样品的吸光度，结果表明－17℃条件下避光保存的样品稳定性最好。

Microwave-assisted Extraction of Fresh Allium tuberosum L (Shallot) Oil

Microwave-assisted solvent extraction at low temperature was used to separate flavor components in fresh shallot. The optimal extraction procedure was investigated, and the stability of fresh shallot product stored at different temperatures (30, 5, －7, －17 ℃) for 30 d was evaluated based on a fact that there is a correlation between freshness and colority of shallot oil. Fresh shallot was first extracted with salad oil once and then extracted with a mixture consisting of acetone and petroleum ether (1:1, V/V) twice, and finally shallot oil was obtained; and the optimal extraction conditions were as follows: microwave power 200 W, extraction temperatures 45 ℃, solvent/material ratio 2:1, and extraction time 5 min for 3 times. The best storage temperature for shallot oil was －17 ℃.