超声-微波协同提取青稞β-葡聚糖

Ultrasonic-microwave synergistic extraction of β-glucan from hull-less barley

以β-葡聚糖得率为试验指标,采用超声-微波协同法提取青稞麸皮β-葡聚糖,利用单因素及正交试验优化其提取工艺,并与水提法、超声法和微波法的提取效果进行对比。采用扫描电镜观察青稞麸皮粉表面结构的变化,初步分析超声-微波协同提取的机制。结果表明,最佳工艺参数为:超声功率250 W、超声时间20 min、微波功率800 W、微波时间3 min、料液比1∶25(g∶m L),β-葡聚糖得率为2. 29%;超声-微波协同法与水提、超声和微波法相比,得率分别提高了120. 19%、57. 93%、18. 65%。扫描电镜的结果显示,水提法使麸皮粉产生溶胀作用,结构由紧致变得松散;超声处理使麸皮粉片状颗粒变得更加细小;微波的热效应使麸皮粉因迅速受热而结构膨化、体积增大;而超声-微波协同法使麸皮粉的结构变得膨大疏松、细碎多孔。这说明β-葡聚糖的得率与麸皮结构的破坏程度可能具有一定的相关性。

The extraction yield of β-glucan from hull-less barley bran by ultrasonic-microwave synergistic method was studied.Single factor experiments and orthogonal tests were used to optimize the extraction conditions.Additionally,effects of ultrasonic-microwave synergistic extraction were compared against water extraction,ultrasonic extraction,and microwave extraction.Changes in surface structure of the hull-less barley bran powder were observed by scanning electron microscopy to investigate the mechanism of ultrasonic-microwave synergistic extraction.The results showed that the optimal conditions were as follows:sonicated at 250 W for 20 min,microwaved at 800 W for 3 min,and the solid to liquid ratio was 1∶25 (g∶mL).Under this condition,the yield of β-glucan was about 2.29%.The yield of ultrasonic-microwave synergistic extraction in comparison to water extraction,ultrasonic extraction,and microwave extraction increased by 120.19%,57.93% and 18.65%,respectively.Scanning electron microscopy showed that water extraction caused swelling of the bran powder,and its structure became loose from tightness.Ultrasonic extraction made the flakes of bran powder finer.The thermal effect of microwave caused the bran powder to be puffed and enlarged due to rapid heating.The ultrasonic-microwave synergistic method made the structure of the bran powder bulky,loose,and porous.Overall,the yield of β-glucan may have a certain correlation with the damaging level of the bran structure.