绿豆皮纤维素的超声波-微波联合辅助提取及其性质研究

Study on Cellulose Extraction from Mung Bean Hull by the Ultrasonic Microwave-Assisted Alkaline Extraction and Its Properties

以绿豆皮为原料,采用超声波-微波联合辅助碱法提取其中的纤维素,研究了Na OH质量分数、Na OH添加量、超声波-微波联合作用时间、微波功率及脱色时间这5个因素对绿豆皮纤维素得率、膨胀力及持水力的影响,并采用傅里叶变换红外光谱(FT-IR)对绿豆皮纤维素的微观结构进行了表征。结果表明:与碱提取法、超声波或微波单独辅助碱提取法相比,超声波-微波联合辅助碱提取法能够有效的提高绿豆皮纤维素的得率并改善其理化性质。通过单因素试验得到了绿豆皮纤维素提取的最佳工艺条件:Na OH质量分数10%、Na OH添加量15 m L/g、超声波-微波联合作用时间15 min、微波功率300 W、脱色时间90 min,在此条件下,获得的绿豆皮纤维素得率为44.91%,膨胀力为4.01 m L/g,持水力为7.16 g/g。绿豆皮纤维素的红外光谱分析结果表明,超声波-微波联合辅助碱法提取的绿豆皮纤维素特征峰没有发生明显变化,且木质素残留较少。本研究结果可以为废弃绿豆皮的再利用提供参考。

Cellulose was extracted from mung bean hull by ultrasonic microwave - assisted alkaline extraction.The effects of five factors on the yield, swelling capacity and water holding capacity of mung bean hull cellose were investigated ineluding NaOH, the addition of NaOH, ultrasonic mierowave synergy time, mierowave power and decol- oring time, and the microstruetures of mung bean hull cellulose were characterized by FT - IR. The contrast test re- sults showed that ultrasonic microwave - assisted alkaline extraction method eould effeetively improve the yield and physieochemieal properties of mung bean hull cellulose, compared with alkaline extraction, ultrasonic - assisted alka- line extraction and microwave - assisted alkaline extraction. According to the single factor experiment results, the op- timal technology parameters were as follows： the mass fraetion of NaOH： 10%, the addition of NaOH： 15 mL/g, ul- trasonie microwave synergy time： 15 rain, microwave power： 300 W, decoloring time： 90 rain; and under the condi- tions, the yield of mung bean hull cellulose was 44.91%, the swelling eapacity was 4.01 mL/g, and the water hold- ing capacity was 7.16 g/g. The infrared spectrum analysis results showed that the eharaeteristic peak of mung bean eellulose extracted by alkali with ultrasonie mierowave- assisted had no obvious change and the cellulose had less re- sidual lignin . The results eould provide a referenee for the abandoned mung bean hull recycling.