菠萝蜜淀粉-月桂酸复合物的理化特性研究

淀粉与油脂热加工过程中会产生大量淀粉-脂质二元复合物,这会显著影响淀粉基产品的品质、保质期、物理化学特性等。菠萝蜜是新型小颗粒、直链淀粉含量高的热带特色淀粉资源。以木薯和玉米两种淀粉与菠萝蜜淀粉同为A型结晶的淀粉作参照,探究加热过程中菠萝蜜原淀粉与月桂酸形成复合物的复合指数、糊化特性、粒径分布、颗粒形貌和短程有序性。实验结果表明:与木薯淀粉和玉米淀粉相比,菠萝蜜淀粉表现出最高的直链淀粉含量,粒径分布更小更均一,最高的短程有序性,更规则且光滑的颗粒形貌,偏低的峰值黏度和相对结晶度。与木薯淀粉-月桂酸复合物和玉米淀粉-月桂酸复合物相比,菠萝蜜淀粉-月桂酸复合物显示出最高的复合指数,较高的最终黏度和相对结晶度,粒径较小且表面光滑,偏低的峰值黏度和短程有序性。研究结果表明月桂酸的添加增强了菠萝蜜淀粉的抗剪切能力和热稳定性；改变了淀粉的颗粒形貌,使原来规则的半球形颗粒变成不规则块状,并增大了颗粒粒径；阻碍了淀粉重结晶,从而导致相对结晶度和短程有序性降低。这些研究结果可为热处理过程中菠萝蜜淀粉与油脂特别是脂肪酸相互作用的研究提供理论依据,为进一步开发利用热带特色淀粉资源提供技术支撑。

Study on Physicochemical Properties of Jackfruit Seed Starch-Laurel Acid Complexes

During thermal processing of starch and lipid, a large amount of starch-lipid binary complexes would be produced, which could significantly affect the quality, shelf life, and physicochemical properties of starch-based products. Jackfruit, a new type of tropical characteristic starch resource with high extraction rate and small particle size, was selected as a raw material to carry out the research. Therefore, the physicochemical properties including complexation index, pasting properties, particle size distribution, particle morphology and short-range order of jackfruit seed starch-lauric acid complexes were investigated. The cassava starch and corn starch, possessing same A-type crystalline with jackfruit seed starch, were selected as experimental reference. The results showed that jackfruit seed starch had the highest amylose content, lowest particle size distribution with highest particle size uniformity and short-range order value in comparison with cassava starch and corn starch. Besides, it showed the smallest, most regular uniform and smoothest particles, and the lower peak viscosity and relative crystallinity. Compared with complexes of cassava starch-lauric acid and corn starch-lauric acid, the complexes of jackfruit seed starch-lauric acid exhibited the highest complexation index, and higher final viscosity and relative crystallinity, more regular and smooth particle morphology with the lower peak viscosity and short-range order. In summary, shear resistance and thermal stability of jackfruit seed starch were strengthened by addition of lauric acid. The particle shape was changed from the original regular hemispherical particles to irregular lumps. And the size of the particles was increased. The recrystallization of starch was delayed, resulting in a significant decrease in relative crystallinity and short-range order. This study might provide a theoretical basis for comprehensive application of starch-basis food.