超高静压改性麦麸对其功能性质的影响

本实验以小麦麸皮为原料,采用单因素试验研究麦麸粒度、处理时间、处理压强和改性麦麸质量分数对小麦麸皮功能性质的影响,通过扫描电子显微镜和傅里叶变换红外光谱仪分析了麦麸改性前后的超微结构和官能团。结果:在麦麸粒度40目、处理时间20 min、压强400 MPa、麦麸质量分数20%条件下,麦麸可溶性膳食纤维质量分数最高、阳离子交换能力最强、脂肪酶活力最低;在麦麸粒度50目、处理时间15 min、压强400 MPa、麦麸质量分数20%条件下,麦麸持水力和持油力较高;在麦麸粒度40目、处理时间25 min、压强300 MPa、麦麸质量分数15%条件下,麦麸亚硝酸根清除率较强;在麦麸粒度50目、处理时间25 min、压强500 MPa、麦麸质量分数25%条件下,麦麸胆固醇吸附能力较强。扫描电子显微镜观察结果显示超高静压破坏了麦麸膳食纤维的结构,使其结构变得疏松,傅里叶变换红外光谱分析结果表明超高静压可以破坏分子间的共价键,使纤维素降解,不溶性膳食纤维转化为可溶性膳食纤维。通过本实验改性的麦麸具有较好的功能特性,有很好的应用前景。

Functional Properties of High Hydrostatic Pressure Modified Wheat Bran

In this experiment, wheat bran was ground and suspended in distilled water before being treated by high hydrostatic pressure (HHP) in an effort to explore the effects of pressure, holding time, particle size, and wheat bran concentration on functional properties of wheat bran, and the ultrastructure and functional groups of wheat bran before and after modification were analyzed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy. Under the conditions of pressure 400 MPa, holding time 20 min, particle size 40 meshes, and wheat bran concentration 20%, modified wheat bran had the highest soluble dietary fiber (SDF) content and cation exchange capacity and the lowest lipase activity. Under the conditions of pressure 400 MPa, holding time 15 min, particle size 50 meshes, and wheat bran concentration 20%, the water-holding capacity and oil-holding capacity were higher. Under the conditions of pressure 300 MPa, holding time 25 min, particle size 40 meshes, and wheat bran concentration 15%, the nitrite scavenging ability was stronger. Under the conditions of pressure 500 MPa, holding time 25 min, particle size 50 meshes, and wheat bran concentration 25%, the cholesterol adsorption capacity was stronger. SEM results showed that HHP destroyed the structure of dietary fiber in wheat bran and made its structure loose. FTIR measurement confirmed that HHP could destroy intermolecular covalent bonds and consequently degrade cellulose and convert insoluble dietary fiber (IDF) to SDF. The modified wheat bran has good functional properties and is promising in the future.