Effects of lecithin/oil ratio in salad dressing on the bioavailability of fat soluble micronutrients in salad vegetables

Abstract

The objectives were to determine the effects of the lecithin/oil ratio in salad dressing on: 1) the absorption of carotenoids, phylloquinone and tocopherols in salad vegetables; 2) the absorption of retinyl palmitate formed from the ingested α‐ and β‐carotene. Twelve healthy women 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 soybean lecithin. The order in which the salads were consumed was randomly assigned; salads were separated by ≥ 2 week. Blood samples were collected at baseline and 2, 3.5, 5, 7, and 9.5 h postprandially. Chylomicron and large very low density lipoprotein (VLDLA) fractions were analyzed by HPLC with coulometric array electrochemical detection. In each lipoprotein fraction, there were no differences among salad dressings in the area under the curves (AUCs) for the fat‐soluble micronutrients. The exception was a decrease in the AUC for phylloquinone in the chylomicron fraction when the salad dressing oil containing 4% lecithin was compared with that containing 0% lecithin (P < 0.02). In conclusion, the added lecithin in the oil in the salad dressing did not affect the intestinal absorption of fat soluble micronutrients with the exception of vitamin K1. Supported by Unilever R&D.