Effect of acute ingestion of fresh and stored lettuce (Lactuca sativa) on plasma total antioxidant capacity and antioxidant levels in human subjects

• Published in: British journal of nutrition Vol. 88; no. 6; pp. 615 - 623
• Main Authors: Serafini, Mauro, Bugianesi, Rossana, Salucci, Monica, Azzini, Elena, Raguzzini, Anna, Maiani, Giuseppe
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.12.2002
• Subjects: acute effects; Adult; analysis; Analysis of Variance; antioxidant activity; Antioxidants; Antioxidants - chemistry; Antioxidants - metabolism; Area Under Curve; Ascorbic Acid; Ascorbic Acid - analysis; Ascorbic Acid - metabolism; Bioavailability; Biological and medical sciences; Biological Availability; blood; blood plasma; Caffeic Acids; Caffeic Acids - blood; Carotenoids; Carotenoids - analysis; Carotenoids - metabolism; chemical composition; chemistry; Coumaric Acids; Coumaric Acids - blood; Eating; Feeding. Feeding behavior; Female; Flavonoids; food composition; Food Handling; Food industries; food nutrient losses; Food Packaging; food storage; Free Radicals; Free Radicals - chemistry; Fundamental and applied biological sciences. Psychology; General aspects; Handling, storage, packaging, transport; human nutrition; Humans; Ingestion; Lactuca; lettuce; Male; men; metabolism; Middle Aged; Modified-atmosphere packaging; nutritive value; Oxidation-Reduction; Phenols; Phenols - analysis; Phenols - metabolism; Plasma antioxidant capacity; Polymers; Polymers - analysis; Polymers - metabolism; Quercetin; Quercetin - blood; storage quality; test meals; Time Factors; Vegetables; Vertebrates: anatomy and physiology, studies on body, several organs or systems; women; Vegetables; Bioavailability; Modified-atmosphere packaging; Plasma antioxidant capacity; Human; Redox state; Plasma antioxidant capacity: Modified-atmosphere packaging: Vegetables: Bioavailability; Compositae; Antioxidant; Feeding; Blood plasma; Vegetable crop; Diet; Fresh product; Dicotyledones; Food industry; Angiospermae; Food preservation; Packaging; Spermatophyta; Modified atmosphere; Lactuca sativa
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1079/BJN2002722

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°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≤0·05) 2 and 3 h after fresh lettuce ingestion. Caffeic acid increased significantly at 3 h (P<0·05). Plasma β-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.