To determine the vitamin A value of kale in children and to determine the effect of cooking the kale with either peanut butter or lard on the bioavailability of kale beta-carotene and its bionconversion to vitamin A
Preschool children ( = 37; age 12-36 mo) were randomly assigned to 50 g cooked kale (1.5 mg ß-carotene content) with either 33 g peanut butter (PBG) or with 16 g lard (LG) and a reference dose of 1 mg [13C10] retinyl acetate capsule. Blood samples were processed to serum and analyzed by Negative Chemical Ionization-Gas Chromatography Mass Spectrometry (NCI-GCMS) for the enrichments of [2H] retinol from kale [2H9] ß-carotene and [13C10] retinol from reference dose
The area under curves (AUCs) of molar enrichment at days 1, 2, 3, 6, 15, and 21 after the labeled doses was 56.3 ± 10.5 and 84.8 ± 16.2 (nmole) for [2H] retinol from LG and PBG kale [2H9] ß-carotene respectively. The AUC of [13C10] retinol from reference dose was 432.6 ± 54.9 (LG) and 560.3 ± 156.7 (nmole) (PBG) respectively. The calculated ß-carotene conversion factors were 13.4 ± 3.1 and 11.0 ± 3.9 to 1 (p>0.05) by weight for LG and PBG respectively
This study showed that peanut butter enhances the vitamin A value of kale.