Babu A Surendra, Parimalavalli R, Jagannadham K, Rao J Sudhakara
Department of Food Science and Nutrition, Periyar University, Salem-636011, Tamil Nadu India.
J Food Sci Technol. 2015 Sep;52(9):5745-53. doi: 10.1007/s13197-014-1650-x. Epub 2014 Nov 26.
In the present study sweet potato starch was treated with hydrochloric acid or citric acid at 1 or 5 % concentration and its properties were investigated. Citric acid treatment resulted higher starch yield. Water holding capacity and water absorption index was increased with increased acid concentration. Emulsion properties improved at 5 % acid concentration. The DE value of acid-thinned sweet potato starches was ranged between 1.93 and 3.76 %. Hydrochloric acid treated starches displayed a higher fraction of amylose. X-ray diffraction (XRD) study revealed that all the starches displayed C-type crystalline pattern with varied crystallinity. FT-IR spectra perceived a slight change in percentage intensity of C-H stretch of citric acid modified starches. Starch granules tended to appear less smooth than the native starch granules after acid treatment in Scanning Electron Micrographs (SEM) with granule size ranging between 8.00 and 8.90 μm. A drastic decrease in the pasting profile was noticed in hydrochloric acid (5 %) treated starch. While 5 % citric acid treated starch exhibited higher pasting profile. Differential Scanning Calorimeter (DSC) showed that peak and conclusion gelatinisation temperatures increased with increase in hydrochloric acid or citric acid concentration. Hence citric acid was found to mimic the hydrochloric acid with some variation which suggests that it may have promising scope in acid modification.
在本研究中，用浓度为1%或5%的盐酸或柠檬酸处理甘薯淀粉，并对其性质进行了研究。柠檬酸处理得到了更高的淀粉产率。持水能力和吸水指数随酸浓度的增加而提高。在5%的酸浓度下，乳化性能得到改善。酸解甘薯淀粉的DE值在1.93%至3.76%之间。盐酸处理的淀粉显示出较高的直链淀粉含量。X射线衍射（XRD）研究表明，所有淀粉均呈现C型结晶模式，结晶度各不相同。傅里叶变换红外光谱（FT-IR）显示，柠檬酸改性淀粉的C-H伸缩振动百分比强度有轻微变化。在扫描电子显微镜（SEM）中，酸处理后的淀粉颗粒比天然淀粉颗粒显得不那么光滑，颗粒尺寸在8.00至8.90μm之间。盐酸（5%）处理的淀粉糊化曲线明显下降。而5%柠檬酸处理的淀粉表现出较高的糊化曲线。差示扫描量热仪（DSC）表明，随着盐酸或柠檬酸浓度的增加，峰值和终了糊化温度升高。因此，发现柠檬酸在某些方面与盐酸相似，这表明它在酸改性方面可能有广阔的应用前景。
