title: The poor digestibility of rapeseed protein is balanced by its very high metabolic utilization in humans.
abstract: Rapeseed protein (RP, Brassica napus) is used in only animal feed despite its high nutritional potential for human nutrition. We sought to assess the nutritional quality of rapeseed by measuring its real ileal digestibility (RID) and net postprandial protein utilization (NPPU) in humans fed (15)N-RP. Volunteers equipped with an intestinal tube at the jejunal (n = 5) or ileal level (n = 7) ingested a mixed meal containing 27.3 g (15)N-RP and a total energy content of 700 kcal (2.93 MJ). Dietary N kinetics was quantified in intestinal fluid, urine, and blood sampled at regular intervals during the postprandial period. The RID of RP was 84.0 +/- 8.8%. Dietary N at the ileal level was mostly in the form of undigested protein from both 12S and 2S rapeseed fractions. Aminoacidemia was not significantly increased by meal ingestion. The postprandial distribution of dietary N was 5.4 +/- 1.8% in urinary urea and ammonia, 8.2 +/- 3.4% in body urea, and 7.7 +/- 2.0% in plasma protein 8 h after the meal. The NPPU of RP amounted to 70.5 +/- 9.6% and the postprandial biological value (PBV) was high at 83.8 +/- 4.6%. RP has a low RID in humans compared with other plant proteins but also exhibits a very low deamination rate. Thus, the PBV of RP is excellent in humans, being as high as that of milk protein. We conclude that RP has a high nutritional potential for human nutrition.
authors.affiliation: UMR914 Nutrition Physiology and Ingestive Behavior, INRA-INAPG, 75005 Paris, France. bos@inapg.inra.fr
authors.forename: Cécile
authors.initials: C
authors.lastname: Bos
authors.forename: Gheorghe
authors.initials: G
authors.lastname: Airinei
authors.forename: François
authors.initials: F
authors.lastname: Mariotti
authors.forename: Robert
authors.initials: R
authors.lastname: Benamouzig
authors.forename: Serge
authors.initials: S
authors.lastname: Bérot
authors.forename: Jacques
authors.initials: J
authors.lastname: Evrard
authors.forename: Evelyne
authors.initials: E
authors.lastname: Fénart
authors.forename: Daniel
authors.initials: D
authors.lastname: Tomé
authors.forename: Claire
authors.initials: C
authors.lastname: Gaudichon
mesh_terms: D000328:Adult; D000821:Animal Feed; D000818:Animals; D029741:Brassica rapa / Q000737:chemistry*; D004044:Dietary Proteins / Q000378:metabolism*; D004063:Digestion; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism; D007700:Kinetics; D008297:Male; D009587:Nitrogen Isotopes; D009747:Nutritional Physiological Phenomena; D019518:Postprandial Period
chemical_list: D004044:Dietary Proteins; D009587:Nitrogen Isotopes