玉米纤维胶的理化性质和抗氧化活性研究

Physicochemical Property and Antioxidant Activity of Corn Fiber Gum

摘要:

本文采用碱性过氧化氢法从玉米麸皮中提取两种玉米纤维胶组分，命名为CFG1和CFG2，分别对它们的理化性质、乳化性质和抗氧化活性进行了研究。结果表明CFG1和CFG2的提取率分别为16.3%和5.7%（以玉米麸皮干重计）；在220 ℃以内具有较好的热稳定性，且CFG2呈现出较大的表观粘度。乳化性能分析表明CFG2比CFG1具有较高的乳化活性指数和乳化稳定性指数，且CFG2稳定乳液具有较大的粘度。抗氧化活性结果表明CFG1和CFG2具有显著的DPPH自由基清除活性和氧自由基吸收能力（Oxygen radical absorbance capacity，ORAC），并呈剂量依赖性，当样品浓度为6 mg/mL，CFG1和CFG2的清除率分别达到71.8%和83.1%；此外，CFG1和CFG2的ORAC值分别为69 μmol TE/g和120 μmol TE/g，表明CFG2具有较强的抗氧化活性。CFG的DPPH和ORAC结果表明CFG（尤其针对CFG2）可开发一种具有良好抗氧化活性的天然乳化剂，可广泛应用于食品和医药工业。

Abstract:

Two kinds of corn fiber gum fractions, named CFG1 and CFG2, were extracted from de-oiled and de-starched corn fiber by the alkaline hydrogen peroxide method, and thephysicochemical property, emulsifying capacity and antioxidant activity of CFG1 and CFG2 were investigated. The yields of CFG1 and CFG2 were 16.3 and 5.7%, respectively (based on the dry weight of corn bran). CFG1 and CFG2 showed good thermal stability at 220 ℃ and CFG2 exhibited a higher apparent viscosity. The thermodynamics analysis indicated that both CFG1 and CFG2 had stronger emulsifying activity index and emulsification stability index, and the stable emulsion of CFG2 exhibited higher viscosity. . The antioxidant activity analysis showed that CFG1 and CFG2 had significant DPPH radical scavenging activity and oxygen radical absorption capacity (ORAC) in a dose-dependent manner. The scavenging rates of CFG1 and CFG2 were 71.8 and 83.1%, respectively, at the concentration of 6.0 mg/mL. In addition, the ORAC values of CFG1 and CFG2 were 69 and 120 μmol TE/g, respectively, indicating that CFG2 had stronger antioxidant activity. The DPPH and ORAC results of CFG suggested that CFG (especially for CFG2) could be developed as a natural emulsifying agents with favorable antioxidant activity.