Bos Cécile, Juillet Barbara, Fouillet Hélène, Turlan Lucie, Daré Sophie, Luengo Catherine, N'tounda Rufin, Benamouzig Robert, Gausserès Nicolas, Tomé Daniel, Gaudichon Claire
Department of Nutrition Physiology and Feeding Control, Institut National de la Recherche Agronomique-Institut National Agronomique, Paris-Grignon, and the Department of Gastroenterology, Avicenne Hospital, Bobigny, France.
Am J Clin Nutr. 2005 Jan;81(1):87-94. doi: 10.1093/ajcn/81.1.87.
The quality of cereal protein has been little studied in humans despite its quantitative importance in the diet, particularly in developing countries.
The objective of this study was to determine the nutritional value of wheat protein in humans as assessed by the measurement of their real ileal digestibility and postprandial retention.
Healthy young adults (n = 14) were fitted with an intestinal tube to allow the collection of intestinal fluid in the duodenum or terminal ileum. Subjects received a mixed meal of 136 g wheat toast that contained 24.6 g uniformly and intrinsically [(15)N]-labeled wheat protein. Intestinal fluid, blood, and urine were collected for 8 h postprandially.
The real ileal digestibility of dietary wheat nitrogen amounted to 90.3 +/- 4.3%. The cumulative amount of dietary nitrogen transferred to the deamination pools reached a plateau at 8 h of 24.7 +/- 6.8% of the amount ingested. The urinary excretion of dietary nitrogen in ammonia was high (0.8 +/- 0.3% of ingested dose). The incorporation of dietary nitrogen into serum protein reached 7.0 +/- 1.9% of the meal. Postprandial wheat protein retention was 66.1 +/- 5.8%.
Our results show that wheat proteins had the same true ileal digestibility as did most of the plant proteins already studied in humans, but also that they had a lower postprandial nitrogen retention value. However, this low value was higher than that predicted from the calculation of indispensable amino acid scores, ie, 89% rather than 30-40% of the nutritional value of milk proteins.
尽管谷物蛋白在饮食中具有重要的定量意义，特别是在发展中国家，但对其在人体中的质量研究较少。
本研究的目的是通过测量人体回肠真消化率和餐后潴留率来确定小麦蛋白的营养价值。
健康的年轻成年人（n = 14）安装了肠管，以便在十二指肠或回肠末端收集肠液。受试者食用了136克小麦吐司的混合餐，其中含有24.6克均匀且内在标记的[(15)N]小麦蛋白。餐后8小时收集肠液、血液和尿液。
膳食小麦氮的回肠真消化率为90.3±4.3%。转移到脱氨基池的膳食氮累积量在8小时时达到平台期，为摄入总量的24.7±6.8%。膳食氮以氨形式的尿排泄量较高（占摄入剂量的0.8±0.3%）。膳食氮掺入血清蛋白的量达到餐量的7.0±1.9%。餐后小麦蛋白潴留率为66.1±5.8%。
我们的结果表明，小麦蛋白的回肠真消化率与已在人体中研究的大多数植物蛋白相同，但餐后氮潴留值较低。然而，这个低值高于根据必需氨基酸评分计算预测的值，即牛奶蛋白营养价值的89%而非30 - 40%。
