魔芋葡甘聚糖基复合物-葡萄灰霉的相互作用研究

Study on the interaction between konjac glucomannan-based composites and grape Botrytis cinerea

中文关键词:  魔芋葡甘聚糖  可得然胶  灰霉  气凝胶  相互作用

英文关键词:konjac glucomannan  curdlan  Botrytis cinerea  aerogel  interaction

中文摘要:

      目的 探究天然多糖魔芋葡甘聚糖(konjac glucomannan, KGM)/可得然胶(curdlan, CUD)复合气凝胶(KC)遭受环境微生物葡萄灰霉侵染时两者发生的相互作用。方法 以KGM和CUD为原料, 采用溶胶预冷、真空冷冻干燥制备不同配比的KGM/CUD复合气凝胶(K1C0.6、K1C0.9、K1C1.2), 用灰霉接种处理, 检测气凝胶的重量变化率; 运用扫描电镜、红外光谱和差示扫描量热仪分别分析气凝胶的微观形貌、分子变化和热稳定性; 观察灰霉在气凝胶上的生长适应性。结果 经灰霉作用, KC气凝胶结构坍塌、皱缩, 孔结构严重破坏; 灰霉适宜于气凝胶环境的生长, 生长旺盛, 形态完整, 萌发大量孢子; 气凝胶被侵染的同时吸收大量水分, 促进了作用进程; 红外光谱推测, 侵染后的气凝胶的多糖长链被降解为短链, 无新基团产生; 差示扫描量热仪(differential scanning calorimetry, DSC)分析表明, 侵染后的气凝胶热稳定性明显下降。结论 葡萄灰霉侵染KC气凝胶, 充分利用和降解多糖分子链, 且适应于气凝胶环境, 本研究将为天然多糖复合物的安全和质量检测提供理论依据。

英文摘要:

      Objective To investigate the interaction of konjac glucomannan (KGM)/curdlan (CUD) composite aerogel (KC) exposed to the environmental microorganism grape Botrytis cinerea. Methods Using KGM and CUD as raw materials, the KGM/CUD composite aerogels (K1C0.6, K1C0.9, K1C1.2) with different ratios were prepared by sol precooling and vacuum freeze-drying. The aerogels were inoculated with gray mold to detect the weight change rates. The morphology, molecular changes and thermal stability of aerogel were analyzed by scanning electron microscopy, infrared spectroscopy and differential scanning calorimetry, respectively. The growth adaptability of B. cinerea on aerogel was observed. Results The structure of KC aerogels collapsed and shrunk, and the pore structure was seriously damaged after the action of B. cinerea. It was suitable for the growth of B. cinerea in aerogel environment, with vigorous growth, complete morphology and large number of spore germination. In the process of infection, the aerogel absorbed a lot of water, which promoted the process of action. The infrared spectrum indicated that the long chain of polysaccharide in the infected aerogel was degraded to short chain and no new groups were produced. The differential scanning calorimetry (DSC) analysis showed that the thermal stability of aerogel decreased obviously after infection. Conclusion KC aerogels are infected by B. cinerea, which make full use of and degraded polysaccharide molecular chains, and adapt to the environment of aerogels. This study can provide theoretical basis for the safety and quality detection of natural polysaccharide composites.