The dose-response effects of the amount of oil in salad dressing on the bioavailability of carotenoids and fat-soluble vitamins in salad vegetables

• Main Author: Agustiana, Agatha
• Language: EN
• Published: Iowa State University 2015
• Subjects: Nutrition
• Online Access: http://pqdtopen.proquest.com/#viewpdf?dispub=1596916

<p>The objectives of the study were to define the dose-response relation of the amount of added oil and: 1) the absorption of carotenoids, phylloquinone and tocopherols in salad vegetables and 2) the absorption of retinyl palmitate formed from the ingested provitamin A carotenoids, |A- and |A-carotene. Women (n = 12) each consumed 5 salads containing equivalent amounts of carrot, cherry tomato, romaine lettuce and spinach. The salads with salad dressings containing 0, 2, 4, 8 or 32 g tocopherol-stripped soybean oil were ingested in random order separated by !Y 2 weeks. Blood samples were collected at baseline and 2, 3.5, 5, 7, and 9.5 h postprandially. Chylomicron fractions were extracted and analyzed by HPLC with coulometric array electrochemical detection. When the salads were ingested with 0 g oil, there was negligible absorption of |A- and |A-carotenes, lutein, lycopene, phylloquinone, retinyl palmitate, |A- and |?-tocopherols. For |A- and |A-carotenes, lycopene, retinyl palmitate, and |A- and |?-tocopherols, absorption was increased with each amount of oil compared with 0 g oil (P <0.05). Starting from 4 g oil, all analytes (|A-carotene, |A-carotene, lutein, trans-lycopene, vitamin A, |A-tocopherol, |?-tocopherol, and vitamin K1) showed significant increases in absorption compared with 0 g oil salad dressing. The absorption of each carotenoid and fat-soluble vitamin was highest with 32 g ingested oil (P < 0.002).