Micronutrient deficiencies are still a public health issue in least developed countries. Promoting diet diversification is a promising strategy. Numerous fruits and vegetables are rich in micronutrients, but some of these compounds are poorly bioaccessible. The objective of this study was to identify the biochemical determinants of the micronutrient bioaccessibility in leaves. The contents in cell walls, pectins, tannins, and proteins of the leafy vegetables were assessed, and correlations with the micronutrient bioaccessibitity were explored. The leafy vegetables have interesting nutritional profiles with noticeable amounts in protein, provitamin A (β-carotene), and α-tocopherol for some species. Their cell wall contents greatly varied from 3.4 to 8.7 g/100 g as well as their pectin percentages. Only the perilla and drumstick leaves contained condensed tannins. In fresh leaves, the contents in bioaccessible carotenoids were low. The correlation study highlighted that the carotenoid bioaccessibility was negatively correlated to the pectin contents of the leaves.
Keywords: in vitro digestion; micellarization; pectins; tannins; β-carotene.