丙酮萃取法制取玉米蜡

Extraction of corn wax by acetone

以玉米蜡糊为原料,采用丙酮萃取法制取玉米蜡。通过单因素实验考察萃取时间、萃取温度、料液比、搅拌速率和萃取次数对玉米蜡提取率和纯度的影响。在单因素实验的基础上,以玉米蜡纯度和提取率为考察指标,利用正交实验优化得到最佳工艺条件。结果表明:玉米蜡的最佳制取条件为料液比1∶5、萃取温度50℃、萃取时间70 min、搅拌速率300 r/min、萃取次数4次;在最佳条件下,玉米蜡提取率为66.71%,纯度为97.23%,磷脂含量为0.18%,白度为59.86%,酸值(KOH)为0.99 mg/g,皂化值(KOH)为124.56 mg/g,水分及挥发物为0.03%,熔程为68.01~81.98℃,丙酮残留为14.98 mg/kg。

Corn wax was prepared from corn wax paste with acetone as extraction solvent.The effects of extraction time, extraction temperature, material-liquid ratio, stirring rate and extraction times on the extraction rate and purity of corn wax were investigated by single factor experiment. Then, on the basis of single factor experiment, the optimal process conditions were obtained by orthogonal experiment with purity and extraction rate of corn wax as indexes. The results showed that the optimal extraction conditions were obtained as follows: material-liquid ratio 1∶5, extraction temperature 50℃, extraction time 70 min, stirring rate 300 r/min, extraction 4 times. Under the optimal conditions, the extraction rate, purity, phospholipid content, whiteness, acid value, saponification value, moisture and volatile matter, melting range and acetone residues of corn wax were 66.71%, 97.23%, 0.18%, 59.86%, 0.99 mgKOH/g, 124.56 mgKOH/g, 0.03%, 68.01-81.98℃ and 14.98 mg/kg.