title: Effect of acute ingestion of fresh and stored lettuce (Lactuca sativa) on plasma total antioxidant capacity and antioxidant levels in human subjects.
abstract: The present study investigated whether storage under modified-atmosphere packaging (MAP) affected the antioxidant properties of fresh lettuce (Lactuca sativa). Eleven healthy volunteers (six men, five women) consumed 250 g fresh lettuce, and blood was sampled before (0 h) and 2, 3 and 6 h after consumption. The protocol was repeated 3 d later with the same lettuce stored at 5 degrees C under MAP conditions (O2-N2 (5:95, v/v)). Results showed that after ingestion of fresh lettuce, plasma total radical-trapping antioxidant potential (TRAP), measured as area under the curve, was significantly higher (1.3 (sem 0.3) mmol/l per 6 h; P<0.05) than the value obtained with MAP-stored lettuce (0.1 (sem 0.2) mmol/l per 6 h). Plasma TRAP, quercetin and p-coumaric acid were significantly different from baseline values (P<or=0.05) 2 and 3 h after fresh lettuce ingestion. Caffeic acid increased significantly at 3 h (P<0.05). Plasma beta-carotene levels increased significantly at 6 h (P<0.05). Vitamin C concentrations (mg/l) rose from 10.9 (sem 2.0) to 12.7 (sem 3.0) (P<0.001), 12.7 (sem 2.0) (P<0.01) and 12.9 (sem 3.0) (P<0.05) at 0, 2, 3 and 6 h respectively. No changes were observed after ingestion of MAP-stored lettuce for all the measured markers. Our present results showed that ingestion of MAP-stored lettuce does not modify plasma redox status in healthy subjects. Further research is needed to develop post-harvesting techniques able to preserve the bioactive molecule content of plant food.
authors.affiliation: Antioxidant Research Laboratory at the Unit of Human Nutrition, Istituto Nazionale di Ricerca per gli Alimenti e la Nutrizione (INRAN), Rome, Italy. serafini@inran.it
authors.forename: Mauro
authors.initials: M
authors.lastname: Serafini
authors.forename: Rossana
authors.initials: R
authors.lastname: Bugianesi
authors.forename: Monica
authors.initials: M
authors.lastname: Salucci
authors.forename: Elena
authors.initials: E
authors.lastname: Azzini
authors.forename: Anna
authors.initials: A
authors.lastname: Raguzzini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maiani
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D019540:Area Under Curve; D001205:Ascorbic Acid / Q000032:analysis / Q000378:metabolism; D001682:Biological Availability; D002109:Caffeic Acids / Q000097:blood; D002338:Carotenoids / Q000032:analysis / Q000378:metabolism; D003373:Coumaric Acids / Q000097:blood; D004435:Eating; D005260:Female; D005419:Flavonoids; D005511:Food Handling; D018857:Food Packaging; D005609:Free Radicals / Q000737:chemistry; D006801:Humans; D018545:Lactuca; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D010636:Phenols / Q000032:analysis / Q000378:metabolism; D011108:Polymers / Q000032:analysis / Q000378:metabolism; D011794:Quercetin / Q000097:blood; D013997:Time Factors
chemical_list: D000975:Antioxidants; D002109:Caffeic Acids; D003373:Coumaric Acids; D005419:Flavonoids; D005609:Free Radicals; D010636:Phenols; D011108:Polymers; D002338:Carotenoids; D011794:Quercetin; D001205:Ascorbic Acid; C040048:caffeic acid