微波辐射对小麦胚芽糊化特性与微观结构的影响

Microstructure and Pasting Characteristics of Wheat Germ Treated by Microwave Radiation

为研究微波辐射对小麦胚芽(WG)品质的影响,采用连续式微波装备对WG进行稳定化处理,并用扫描电镜、粘度仪分析了微波辐射对其微观结构、淀粉糊化等特性的影响。结果表明,微波对WG有很好的稳定化效果,在有效钝酶的前提下经微波处理的WG仍可观察到完整的淀粉颗粒,并伴有清晰的轮廓,但随着微波辐射强度的提高,其中油脂、蛋白质及淀粉之间原有的空间结构发生了一定的改变。微波处理后WG的糊化温度由原来的58.5℃升至59.3～65.4℃,根据初始糊化程度的不同,出现具有一定意义的峰值粘度(349～466 BU)和破损值(69～87 BU)。微波处理后的WG中脂肪酸组成和α-维生素E含量无明显改变。研究表明,微波辐射在有效钝酶的同时,对WG的品质也产生了部分影响。但与传统热处理方法相比,微波辐射对WG品质影响程度较小,微波稳定化具有很好的工业化应用前景。

In order to study the impact of microwave radiation on wheat germ （WG） quality, a continuous microwave radiation system was constructed. Scanning electron microscopy and micro-viscometer were used to detect the influence of microwave radiation on microstructure and starch pasting characteristics of WG. The results showed that the continuous microwave radiation system had a good stabilization effect on WG. The majority starch granules in microwave-treated WG were still intact observed by SEM, accompanied by a clear outline. However, with the microwave radiation intensity increased, the original spatial structure changed among starch granule, oil and protein. The gelatinization temperature of microwave treated WG rose to a range of 59.3 - 65.4℃. Depending on their extent of pre-gelatinization, different WG samples gave significantly different peak viscosity （349 -466 BU ） and break down values （69 - 87 BU）. Compared with that of raw WG samples, the fatty acids composition and tocopherol content of WG treated by microwave did not change significantly. The above results showed that microwave radiation did have some effect on WG quality, but less than traditional heating methods. Microwave stabilization should have a good prospect for industrial application.