以蜡提取率为指标,采用乙醇-水-正己烷双液相溶剂法回流提取高粱蜡,应用三因素二次回归通用旋转组合设计,对影响蜡提取的主要因素进行优化。高粱蜡的最佳提取条件为烷料比(mL:g)7.21:1,醇料比(mL:g)9.92:1,提取时间80min,在此条件下高粱蜡提取率的理论值可达0.3018%。在优化条件下进行验证试验提取率为0.2975%。提取的高粱蜡的基本理化性质为:色度(L*a*b*)分别为45.01±0.05、9.60±0.12和14.80±2.26,酸值10.98±0.29,碘值18.94±0.29,皂化值77.53±0.47。高粱蜡熔点为66.5-77.6℃,与巴西棕榈蜡接近,高于米糠蜡、蜂蜡和石蜡。高粱蜡中二十八烷醇和三十烷醇含量分别达到21.97%±0.12%和24.73%±0.22%。

Sorghum wax was extracted by means of organic dissolvent reflux with two-liquid-phase system.Extraction solvent and technological conditions were optimized by response surface methodology (RSM).Based on extraction rate,the optimal extraction conditions were determined as follows:hexane-material ratio 7.21:1,ethanol-material ratio 9.92:1 and extraction time 80 min.The theoretical value of extraction rate was 0.301 8% at the optimum extraction conditions.The actual extraction rate was 0.297 5%.The properties of the extracted sorghum wax as follows:Color intensity (L a b)was 45.01±0.05,9.60±0.12 and 14.80±2.26 respectively;Acid number was 10.98±0.29;Iodine value was 18.94±0.29;Saponification value was 77.53±0.47;Melting range was 66.5℃-77.6℃.The Melting range of sorghum wax was similar to that of carnauba wax,and higher than that of rice bran wax,beeswax,paraffin.The contents of octacosanol and triacontanol of saponified in sorghum wax were 0.065 90% ±0.000 36% and 0.074 2 %±0.000 66%,respectively.