Departamento de Industrias, Facultad de Ciencias Exactas y Naturales, University of Buenos Aires (UBA), Ciudad Universitaria, and National Research Council (CONICET) (1428) Buenos Aires, Argentina.
J Agric Food Chem. 2012 May 30;60(21):5414-22. doi: 10.1021/jf205132m. Epub 2012 May 16.
The hydrolytic and oxidative stability of L-(+)-ascorbic acid (AA) into plasticized pectin films were separately studied in view of preserving vitamin C activity and/or to achieve localized antioxidant activity at pharmaceutical and food interfaces. Films were made with each one of the enzymatically tailored pectins (50%, 70%, and 80% DM; Cameron et al. Carbohydr. Polym.2008, 71, 287-299) or commercial high methoxyl pectin (HMP; 72% DM). Since AA stability was dependent on water availability in the network, pectin nanostructure affected the AA kinetics. Higher AA retention and lower browning rates were achieved in HMP films, and calcium presence in them stabilized AA because of higher water immobilization. Air storage did not change AA decay and browning rates in HMP films, but they significantly increased in Ca-HMP films. It was concluded that the ability of the polymeric network to immobilize water seems to be the main factor to consider in order to succeed in retaining AA into film materials.
分别研究了 L-(+)-抗坏血酸（AA）在增塑果胶膜中的水解和氧化稳定性，以期在药物和食品界面保持维生素 C 活性和/或实现局部抗氧化活性。使用酶法修饰的果胶（50%、70%和 80%DM；Cameron 等人，《碳水化合物聚合物》2008 年，71 期，287-299）或商业高甲氧基果胶（HMP；72%DM）中的每一种制备了薄膜。由于 AA 的稳定性取决于网络中水分的可用性，因此果胶的纳米结构影响 AA 的动力学。在 HMP 薄膜中可以获得更高的 AA 保留率和更低的褐变率，并且其中钙的存在由于更高的水分固定化而稳定了 AA。空气储存不会改变 HMP 薄膜中 AA 的降解和褐变率，但会显著增加 Ca-HMP 薄膜中的 AA 降解和褐变率。结论是，为了成功地将 AA 保留在薄膜材料中，聚合物网络固定水分的能力似乎是需要考虑的主要因素。
