Department of Biotechnology, Korea University, Seoul 02841, Republic of Korea.
Department of Food Science and Biotechnology, Wonkwang University, Iksan, Jeonbuk 54538, Republic of Korea.
Int J Biol Macromol. 2021 Mar 31;174:540-548. doi: 10.1016/j.ijbiomac.2021.01.220. Epub 2021 Feb 2.
This research focused on the structural characteristics of resistant starches (RSs) that were obtained from corn, potato, and sweet potato and esterified by L-malic acid. Further, the unique effect of the degree of substitution (DS) on the crystalline properties was studied. Different starches were allowed to react with 2 M malic acid (pH 1.5) for 12 h at 130 °C. The shapes of the granules and the Maltese-cross shapes of samples were maintained and visible under an optical microscope. The FT-IR spectrum displayed evident carbonyl peaks at 1740 cm, and the onset temperature (T) and gelatinization enthalpy (∆H) gradually decreased as DS increased. The malic acid-treated starches exhibited an increased RS content compared to those of the control. The RS contents of potato, sweet potato, and corn, which were 65.5%, 70.0%, and 89.8% in the uncooked MT-samples, decreased to 57.3%, 63.8%, and 86.7% in the cooked MT-samples, respectively, and exhibited high heat stability; corn starch yielded the highest RS among them. The thermal and malic acid treatments resulted in the partial hydrolysis and rearrangement of the helix structure of crystalline area, which was affected by esterification. The result revealed that the RS content increased as that of DS escalated.
本研究聚焦于通过 L-苹果酸酯化获得的来自玉米、马铃薯和甘薯的抗性淀粉（RS）的结构特性，并进一步研究了取代度（DS）对结晶特性的独特影响。不同的淀粉与 2M 苹果酸（pH 1.5）在 130°C 下反应 12 小时。在光学显微镜下可以观察到颗粒的形状和样品的马耳他十字形状得以保持和可见。FT-IR 光谱在 1740cm 处显示出明显的羰基峰，随着 DS 的增加，起始温度（T）和胶化焓（∆H）逐渐降低。与对照相比，经苹果酸处理的淀粉的 RS 含量增加。生 MT 样品中马铃薯、甘薯和玉米的 RS 含量分别为 65.5%、70.0%和 89.8%，下降至熟 MT 样品中的 57.3%、63.8%和 86.7%，表现出较高的热稳定性；其中玉米淀粉的 RS 含量最高。热和苹果酸处理导致结晶区螺旋结构的部分水解和重排，这受到酯化的影响。结果表明，随着 DS 的增加，RS 含量增加。
