低分子量酵母甘露聚糖的制备及其抗氧化性研究

首先采用高温水提法制备酵母甘露聚糖,然后分别采用微波降解法、超声波降解法、甘露聚糖酶法和H₂O₂降解法四种方法制备低分子量酵母甘露聚糖。对影响降解酵母甘露聚糖的因素进行了研究,并采用正交实验设计进行了工艺优化。同时对未经降解处理的甘露聚糖(YM)和所制备的低分子甘露聚糖(SYM)的体外抗氧化活性进行比较。结果表明,H₂O₂降解法的效果最好,其次是超声波降解法,而微波降解法和甘露聚糖酶法对酵母甘露聚糖几乎没有降解效果。H₂O₂降解法制备低分子量酵母甘露聚糖的最优工艺条件为:甘露聚糖浓度30 g/L、H₂O₂浓度10%、温度95 ℃、时间3 h。在上述工艺条件下,酵母甘露聚糖的重均分子量由76.52 kDa降低到8.07 kDa。抗氧化活性实验发现SYM对羟基自由基、超氧阴离子自由基清除能力均明显高于YM。

Study on Preparation and Its Antioxidant Activity of Yeast Mannan with Low Molecular Weight

Yeast mannan was prepared by hot water extraction, and then microwave, ultrasonic wave, mannanase and H₂O₂treatments were used to degrade yeast mannan. The factors that influenced degradation of yeast mannan under the best degradation method were investigated, and the degradation conditions were optimized using orthogonal experiment method. The antioxidant activities of yeast mannan without degradation (YM) and the prepared low-molecular-weight yeast mannan (SYM) were also investigated in vitro. The results showed that H₂O₂ treatment could effectively degrade yeast mannan, and ultrasonic wave treatment had a little degradation of yeast mannan. However, microwave treatment and mannanase treatment hardly degraded yeast mannan. The best H₂O₂-degradation conditions of yeast mannan were the concentration of mannan 30 g/L, H₂O₂ concentration 10%, temperature 95℃ and reaction time 3 h. Under the best H₂O₂-degradation condition, the weight average molecular weights of yeast mannan decreased from 76.52 kDa to 8.07 kDa. The results also showed that SYM had a stronger scavenging ability to hydroxyl radicals and superoxide anions than YM.