Frias J, Vidal-Valverde C
Instituto de Fermentaciones Industriales, Consejo Superior de Investigaciones Cientifícas, Juan de la Cierva 3, E-28006 Madrid, Spain.
J Agric Food Chem. 2001 May;49(5):2313-7. doi: 10.1021/jf001243d.
The content of thiamine (vitamin B(1)), vitamin E (alpha-, gamma-, and delta-tocopherol) and vitamin A (all-trans-retinol and 13-cis-retinol) in five commercial enteral feeding formulas was studied. These formulas provide a large amount of vitamins: 2.5--3, 3.1, and 1.6-fold above the U.S. daily recommendations (U.S. RDA) for thiamine, vitamin E, and vitamin A, respectively. The stability of thiamine and vitamins E and A of two of the enteral feeding formulas was followed throughout 9 months of storage in the dark at 4 degrees, 20 degrees, and 30 degrees C. According to our results in all of the storage conditions studied, the enteral formula covered the U.S. RDA levels for thiamine and vitamin E, but in the case of vitamin A the U.S. RDA requirements are met only when the enteral sample has been kept in storage less than 3 months. After 6 months of storage, the decrease in vitamin A was so drastic that the level of vitamin covered only 0.9--0.3-fold of the U.S. RDA and after 9 months it covered only 0.2--0.0-fold of U.S. RDA. The manufacturer shelf life of the formula studied was 1 year; and, because enteral feeding solutions are often placed in storage conditions of uncontrolled temperature and humidity, these results should be taken into consideration with regard to the shelf life.
研究了五种市售肠内营养配方食品中硫胺素（维生素B₁）、维生素E（α-、γ-和δ-生育酚）以及维生素A（全反式视黄醇和13-顺式视黄醇）的含量。这些配方食品提供了大量的维生素：硫胺素、维生素E和维生素A的含量分别比美国每日推荐摄入量（美国RDA）高出2.5至3倍、3.1倍和1.6倍。在4℃、20℃和30℃黑暗条件下储存9个月的过程中，跟踪了两种肠内营养配方食品中硫胺素、维生素E和维生素A的稳定性。根据我们在所有研究储存条件下的结果，肠内配方食品中硫胺素和维生素E的含量达到了美国RDA水平，但对于维生素A，只有在肠内样本储存时间少于3个月时才能满足美国RDA的要求。储存6个月后，维生素A的下降非常显著，其含量仅为美国RDA的0.9至0.3倍，储存9个月后，仅为美国RDA的0.2至0.0倍。所研究配方食品的制造商保质期为1年；而且，由于肠内营养溶液常常置于温度和湿度不受控制的储存条件下，在考虑保质期时应考虑这些结果。
