铁皮石斛多糖液态发酵工艺及其抗氧化活性研究

探讨液态发酵铁皮石斛多糖的最佳工艺及其抗氧化活性。采用单因素及正交实验研究了发酵温度、转速、p H和发酵时间对发酵工艺的影响,得到了液态发酵的最优条件:发酵温度28℃,p H4.5,转速170 r/min,发酵时间54 h;发酵后铁皮石斛水提多糖的总抗氧化能力、清除DPPH及ABTS自由基能力均有所提高,而且均具有很强的量效关系;发酵后石斛多糖的平均分子量由4.234×10~5降为1.077×10~5,推测发酵多糖抗氧化能力的提高可能与微生物发酵过程导致石斛多糖分子量的减小有关。 

Study on polysaccharides submerged fermentation from Dendrobium officinale and its antioxidant activity

In this paper, the suitable submerged fermentation method and antioxidant activity of Dendrobium officinale polysaccharide ( DOP) were studied. The effects of temperature, agitation speed, p H and time on yield of cerevisiae were investigated on the basis of single-factor experiments and orthogonal test for fermentation. The optimum fermentation process parameters were fermentation temperature 28 ℃, p H 4.5, agitation speed 170 r/min, fermentation time 54 h. The total antioxidant capacity, DPPH and ABTS free radical scavenging capacity of Dendrobium officinale polysaccharide has been improved by fermentation, and has very strong dose-response relationship.Average molecular weight of polysaccharide by water extraction and fermentation measured by the GPC-MALLS system showed that it was decreased from 4.234 × 10⁵ to 1.077 × 10⁵ after fermentation.The improvement of antioxidant capacity may be related to the decrease of molecular weight.