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玉米淀粉顆?;镜慕Y(jié)構(gòu)特點如何看出?

玉米淀粉顆?;镜慕Y(jié)構(gòu)特點如何看出?

網(wǎng)址:http://www.qylxschool.cn 手機頁面二維碼 2023-02-11 14:36:50    

玉米淀粉顆粒基本的結(jié)構(gòu)特點是由厚度在100~400nm的無定形層與結(jié)晶層交替組成的天然多晶體系,這樣的結(jié)構(gòu)被稱為輪紋結(jié)構(gòu)。
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.
通常結(jié)晶區(qū)約為顆粒體積的15%~30%,而無定形區(qū)的構(gòu)造今還沒有較好的確定方法。結(jié)晶區(qū)和無定形區(qū)間無明確的分界線,變化是漸進的。由于可見光偏振取決于可見光的波長順序(100~1000nm),因此支鏈淀粉的徑向組織方式被認為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.
從更高層次的分子排列來看,X射線衍射法研究表明顆粒內(nèi)部存在9~10nm的片段??梢詺w因于顆粒內(nèi)部交替出現(xiàn)的結(jié)晶層與無定形層,并通過側(cè)鏈的簇狀結(jié)構(gòu)形成,從支鏈放射狀的地方分叉。這也是淀粉顆粒共有的特點,與淀粉來源無關(guān)。
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.
玉米淀粉顆粒
不同來源的淀粉顆粒具有相應(yīng)的特征顆粒形貌,如圖11所示,有球形、橢球形、多角形、片狀及不規(guī)則管狀。在偏光顯微鏡下觀察,會呈現(xiàn)偏光十字或馬耳他十字,這是淀粉粒具有晶體結(jié)構(gòu)的重要標(biāo)志。雙折射性是由于淀粉粒的高度有序性(方向性)所引起的,高度有序的物質(zhì)都有雙折射性。
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證明了淀粉的球晶結(jié)構(gòu)的存在,表明微晶的主軸是徑向的。而瘦長形顆粒的兩極及中線區(qū)域的偏光十字沒有變化,說明微晶其微小并呈現(xiàn)多向性,十字的交叉點位于粒心,因此可以進行粒心的定位。
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.
不同種類淀粉粒的偏光十字的位置、形狀和明顯程度不同,可依此鑒別淀粉種類。例如,馬鈴薯和綠豆淀粉的偏光十字比較明顯,而大米淀粉明顯程度稍差。鏈淀粉含量與顆粒形態(tài)特征方面存在直接相關(guān)性。鏈淀粉含量越高,玉米淀粉中能找到的長條狀顆粒越多。不同來源的淀粉粒徑不同,一般分布在0.1~200.0m之間。更多相關(guān)內(nèi)容就來我們網(wǎng)站http://www.qylxschool.cn咨詢了解吧!
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.qylxschool.cn Ask about it!