荞麦麸皮中黄酮类物质的提取纯化及壳聚糖复合膜的制备

Extraction and Purification of Flavonoids from Buckwheat Bran and Preparation of Chitosan Composite Membrane

为了提高荞麦的利用率以及延长鲜切果蔬的货架期,以工业废渣荞麦麸皮为原料,采用超声辅助醇溶法提取荞麦麸皮中黄酮类物质,提取工艺为:70%(体积分数)乙醇,提取温度为50℃,料液比为1:40(m/V),超声波频率为2500 Hz,提取时间40 min,荞麦麸皮中黄酮类物质的得率为29.3 mg/g。测定了荞麦麸皮黄酮对2种鲜切果蔬腐败菌的抑菌效果,最小抑菌浓度实验结果显示:荞麦麸皮黄酮对大肠杆菌、荧光假单孢菌的最低抑菌浓度(MIC)分别为0.595、1.190 mg/mL,对大肠杆菌、荧光假单孢菌的最低杀菌浓度(MBC)分别为1.19、2.38 mg/mL。将提取出的黄酮与壳聚糖混合后制备成复合膜,制作工艺为:黄酮-壳聚糖比值为27%,甘油-壳聚糖比值为1:3。制成的可食性复合膜具有良好的抑菌性能且安全无毒、操作简单、成本较低。

In order to improve the utilization of buckwheat and prolong the shelf life of fresh cut fruits and vegetables, the induslrial waste residue of buckwheat bran was used as raw materials to extract flavonoids by ultrasonic-assisted alcohol dissolution method. The extraction process was!as follows： ethanol 70% （volume fraction）, the extraction temperature 50℃, the ratio of material to liquid 1：40 （m/V） The ullrasonic frequency was2500 Hz and the extraction time was 40 min. The yield of flavonoids in buckwheat bran was 29.3 mg/g. The bacteriostatic effect of buckwheat bran flavonoids on the two kinds spoilages of fresh fruits and vegetables was studied, the results showed that the minimum inhibitory concentration （MIC） of buckwheat bran flavonoids on Escherichia coli and Pseudomonasfluorescens were 0.595 and 1.19 mg/mL, respectively. The minimal bactericidal concentration （MBC） of Escherichia coli and Pseudomonas fluorescens were 1.19 and 2.38 mg/mL, respectively. The extracted flavonoids were mixed with chitosan and Freeze-dried to prepare composite membrane. The reparation process was as follows： flavonoid-chitosan ratio 27%, and glycerol-chitosan ratio 1： 3. The composite film had a good antibacterial effect and was safe, simple operation, and low-cost.