Effects of lecithin in salad dressing on the plasma appearance of fat‐soluble micronutrients consumed in salads: contributions of chylomicrons and large VLDL (645.16)

Abstract

The objectives were to investigate the effects of the lecithin/oil ratio in salad dressing on the absorption of: 1) carotenoids, phylloquinone, and tocopherols from salad vegetables; 2) retinyl palmitate formed in the intestine from the provitamin A carotenoids. An additional objective was to investigate the roles of plasma chylomicrons and large very‐low‐density lipoproteins (VLDLA) in the transport of the newly‐absorbed fat‐soluble micronutrients. Healthy women (n = 12) each consumed 3 identical salads with 3 different salad dressings, which each contained 4 g of phylloquinone‐ and tocopherol‐stripped soybean oil. The soybean oil contained (by wt) 0%, 1% or 4% added hydroxylated soy lecithin. The order in which the salads were consumed was randomly assigned; salads were separated by 蠅 2 weeks. Blood was collected at baseline and 2, 3.5, 5, 7, and 9.5 h postprandially. Chylomicrons and VLDLA were analyzed by HPLC with coulometric array electrochemical detection. The hydroxylated soy lecithin in the amounts added to the oil in the salad dressing did not enhance the absorption of carotenoids, retinyl palmitate, phylloquinone, or tocopherols. The majority of the absorbed carotenoids, retinyl palmitate, and phylloquinone were contained within large VLDL (P < 0.01). Thus lipoproteins and/or their remnants in this subfraction have a major role in the transport of newly‐absorbed carotenoids and fat‐soluble vitamins.