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玉米淀粉颗粒基本的结构特点如何看出?

玉米淀粉颗粒基本的结构特点如何看出?

网址:http://www.1958666.com 手机页面二维码 2023-02-11 14:36:50    

玉米淀粉颗粒基本的结构特点是由厚度在100~400nm的无定形层与结晶层交替组成的天然多晶体系,这样的结构被称为轮纹结构。
The basic structural feature of corn starch granules is a natural polycrystalline system consisting of an amorphous layer and a crystalline layer with a thickness of 100-400 nm. Such a structure is known as the wheel structure.
通常结晶区约为颗粒体积的15%~30%,而无定形区的构造今还没有较好的确定方法。结晶区和无定形区间无明确的分界线,变化是渐进的。由于可见光偏振取决于可见光的波长顺序(100~1000nm),因此支链淀粉的径向组织方式被认为是造成光偏振的原因。
Generally, the crystalline area is about 15%~30% of the particle volume, while the structure of the amorphous area has not been well determined yet. There is no clear boundary between the crystalline zone and the amorphous zone, and the change is gradual. Because the polarization of visible light depends on the wavelength order of visible light (100~1000 nm), the radial structure of amylopectin is considered to be the cause of light polarization.
从更高层次的分子排列来看,X射线衍射法研究表明颗粒内部存在9~10nm的片段。可以归因于颗粒内部交替出现的结晶层与无定形层,并通过侧链的簇状结构形成,从支链放射状的地方分叉。这也是淀粉颗粒共有的特点,与淀粉来源无关。
From a higher level of molecular arrangement, X-ray diffraction shows that there are 9~10 nm fragments in the particles. It can be attributed to the alternating crystal layer and amorphous layer inside the particles, which are formed through the cluster structure of the side chain and bifurcate from the radial part of the branch chain. This is also a common characteristic of starch granules, which has nothing to do with the source of starch.
玉米淀粉颗粒
不同来源的淀粉颗粒具有相应的特征颗粒形貌,如图11所示,有球形、椭球形、多角形、片状及不规则管状。在偏光显微镜下观察,会呈现偏光十字或马耳他十字,这是淀粉粒具有晶体结构的重要标志。双折射性是由于淀粉粒的高度有序性(方向性)所引起的,高度有序的物质都有双折射性。
Starch particles from different sources have corresponding characteristic particle morphology, as shown in Figure 11, including spherical, ellipsoidal, polygonal, flaky and irregular tubular. When observed under a polarizing microscope, there will be a polarizing cross or a Malta cross, which is an important sign of the crystal structure of starch granules. Birefringence is caused by the high order (directionality) of starch particles. Highly ordered substances have birefringence.
淀粉偏光十字的存在证明了淀粉的球晶结构的存在,表明微晶的主轴是径向的。而瘦长形颗粒的两极及中线区域的偏光十字没有变化,说明微晶其微小并呈现多向性,十字的交叉点位于粒心,因此可以进行粒心的定位。
The existence of polarized cross of starch proves the existence of spherical structure of starch, indicating that the main axis of microcrystals is radial. However, the polarized cross of the two poles and the central line of the thin and elongated particles does not change, indicating that the microcrystals are small and multi-directional, and the intersection of the cross is located at the center of the particles, so the center of the particles can be located.
不同种类淀粉粒的偏光十字的位置、形状和明显程度不同,可依此鉴别淀粉种类。例如,马铃薯和绿豆淀粉的偏光十字比较明显,而大米淀粉明显程度稍差。链淀粉含量与颗粒形态特征方面存在直接相关性。链淀粉含量越高,玉米淀粉中能找到的长条状颗粒越多。不同来源的淀粉粒径不同,一般分布在0.1~200.0m之间。更多相关内容就来我们网站http://www.1958666.com咨询了解吧!
The position, shape and apparent degree of the polarized cross of different types of starch grains are different, so the starch types can be identified according to this. For example, the polarizing cross of potato and mung bean starch is relatively obvious, while the apparent degree of rice starch is slightly poor. There is a direct correlation between amylose content and particle morphology. The higher the content of amylose, the more elongated particles can be found in corn starch. The grain size of starch from different sources is different, and generally distributed between 0.1 and 200.0m. Come to our website for more relevant content http://www.1958666.com Ask about it!