Department of Food Science and Human Nutrition, Iowa State University, Ames, IA 50011, USA.
Carbohydr Polym. 2013 Jan 30;92(1):120-7. doi: 10.1016/j.carbpol.2012.08.092. Epub 2012 Sep 1.
This study aimed to understand effects of lipids, including corn oil (CO), soy lecithin (SL), palmitic acid (PA), stearic acid (SA), oleic acid (OA), and linoleic acid (LA), on the enzymatic hydrolysis and physical properties of normal corn (NCS), tapioca (TPS), waxy corn (WCS), and high-amylose corn (HA7) starch, and to elucidate mechanisms of interactions between the starches and lipids. After cooking with the lipids (10%, w/w, dsb), NCS, TPS, and HA7 showed significant decreases in enzymatic hydrolysis, and their DSC thermograms displayed amylose-lipid-complex dissociation peaks except with the CO. (13)C NMR spectra of amylodextrin with CO showed downfield changes in the chemical shifts of carbons 1 and 4 of the anhydroglucose unit, indicating helical complex formation. Generally, free fatty acids (FFAs) reduced, but SL increased the peak viscosities of starches. FFAs and SL decreased, but CO increased the gel strength of NCS. These lipids displayed little impacts on the enzymatic hydrolysis and physical properties of WCS because it lacked amylose.
本研究旨在了解脂质（包括玉米油（CO）、大豆卵磷脂（SL）、棕榈酸（PA）、硬脂酸（SA）、油酸（OA）和亚油酸（LA））对普通玉米（NCS）、木薯淀粉（TPS）、蜡质玉米（WCS）和高直链玉米（HA7）淀粉的酶解和物理性质的影响，并阐明淀粉与脂质之间相互作用的机制。将这些脂质（10%，w/w，dsb）与 NCS、TPS 和 HA7 一起烹饪后，发现它们的酶解程度显著降低，其 DSC 热图谱除了 CO 之外都显示出直链淀粉-脂质复合物解离峰。（13）C NMR 图谱显示，与 CO 一起的支链淀粉中的碳 1 和 4 的化学位移发生了向场变化，表明形成了螺旋复合物。一般来说，游离脂肪酸（FFAs）减少，但 SL 增加了淀粉的峰值黏度。FFAs 和 SL 减少，但 CO 增加了 NCS 的凝胶强度。这些脂质对 WCS 的酶解和物理性质影响较小，因为它缺乏直链淀粉。
