【作者】 唐乐乐； 杨瑞金； 华霄； 张文斌； 赵伟；

【Author】 Lele Tang;Ruijin Yang;Xiao Hua;Wenbin Zhang;Wei Zhao;School of Food Science and Technology,Jiangnan University;

【机构】 江南大学食品学院；

【摘要】 葡萄糖氧化酶（GO）（EC 1.1.3.4）是最具潜力的取代KBrO₃的酶制剂。由GO催化反应生成的H₂O₂一定意义上能提高面团的流变性质和持气能力,但游离GO存在氧化速度过快,稳定性差及易失活等不足,使其不能完全取代溴酸钾。GO催化速度很快,在面团形成中就生成了H₂O₂,过早生成的H₂O₂会使面团变干变硬,最终导致焙烤品质较差。因此,本研究拟采用固定化的方法将GO固定在壳聚糖-三聚磷酸钠形成的微胶囊中,不仅能减缓H₂O₂的释放速度,还能提高酶的稳定性。以壳聚糖和三聚磷酸钠为复合缓释壁材,制备具有缓释效果的GO,研究不同因素对缓释GO酶活回收率和缓释效果的影响。结果显示,制备具有缓释效果GO的最佳条件为:壳聚糖浓度1.25%,三聚磷酸钠浓度5 mg/mL,GO浓度6 mg/mL,壳聚糖:三聚磷酸钠=3:1,此时GO酶活回收率最高达到83.74%,且显示出较好的缓释性能。本研究提供了一种具有缓释效果的GO的制备方法,在焙烤工业中具有一定的工业前景和市场潜力。更多还原

【Abstract】 Glucose oxidase（GO）（EC 1.1.3.4） is one of the most effective alternative to KBrO₃.Hydrogen peroxide（H₂O₂） produced during GO reaction promotes the formation of disulfide linkages in the gluten networks and consequently improves dough handling properties,better gas retention capability and bread quality.However,free GO has some deficiencies in replacing KBrO₃,such as fast oxidation,low stability and thermal-inactivation in the baking stage.Fast oxidation will cause rapid release of H₂O₂ at the beginning stage,resulting in over-developed dough and low volume and poor crumb of bread.Immobilization is an effective method to control the release of H₂O₂ and improve the stability of GO.Thus,controlled-release GO（GO-loaded chitosan-sodium tripolyphosphate（TPP） microparticles） for breadmaking was investigated in this study.GO-loaded chitosan-TPP microparticles was performed by ionotropic gelation.Four factors affecting the microparticles properties were varied;chitosan concentration,TPP concentration,chitosan to TPP ratios,GO concentration.GO-loaded chitosan-TPP microparticles was collected by centrifugation and dried by freeze drying.The enzyme activity of GO-loaded chitosan-TPP microparticles was determined and enzyme activity recovery of GO was calculated.The release of H₂O₂ was investigated by the decline of pH qualitatively in phosphate buffer solution containing glucose as substrate for 3h.It was found that the optimum conditions for GO-loaded chitosan-TPP microparticles were chitosan concentration 1.25%（w/v）,TPP concentration 5 mg/mL,chitosan to TPP 3:1,GO concentration 6 mg/mL.Under this condition the recovery of enzyme activity reached 83.74%,and the controlled-release GO showed better slow release of H₂O₂ compared with free GO.This investigation has suggested a promising way to prepare potential breadmaking improver by controlled-release GO.更多还原