Selenium Bioaccessibility and Speciation in Selenium-Enriched Lettuce: Investigation of the Selenocompounds Liberated after in Vitro Simulated Human Digestion Using Two-Dimensional HPLC-ICP-MS.
The evaluation of selenium-enriched vegetables as potential dietary sources of selenium, an essential element for humans, requires an assessment of the plant's accumulation ability as well as of the bioaccessibility and speciation of the accumulated selenium, which influence its biological effects in humans. Lettuce hydroponically grown at three selenite (SeVI)/selenate (SeIV) amendment levels was characterized accordingly. Selenium accumulation in lettuce leaves was greatest with Se(VI) amendment, whereas bioaccessibility was 70% on average in both cases. Selenium speciation in gastrointestinal hydrolysates, characterized by anion and cation exchange HPLC-ICP-MS, showed that Se(IV) was largely biotransformed into organoselenium metabolites, with selenomethionine accounting for 1/3 of the total detected species, whereas Se(VI) was incorporated as such in the edible portion of the plant, with only a small fraction (∼20%) converted into organic species. Taking into account both nutritional quality and safety, the Se(IV)-enriched lettuce appeared more favorable as a potential selenium source for human consumption.
Institute of Chemistry, University of Campinas , CEP 6154, 13083-970 Campinas, SP, Brazil.
Emanueli
E
do Nascimento da Silva
Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità-Italian National Institute of Health , Viale Regina Elena 299, 00161 Rome, Italy.
Federica
F
Aureli
Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità-Italian National Institute of Health , Viale Regina Elena 299, 00161 Rome, Italy.
Marilena
M
D'Amato
Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità-Italian National Institute of Health , Viale Regina Elena 299, 00161 Rome, Italy.
Andrea
A
Raggi
Institute of Chemistry, University of Campinas , CEP 6154, 13083-970 Campinas, SP, Brazil.
Solange
S
Cadore
Department of Food Safety, Nutrition and Veterinary Public Health, Istituto Superiore di Sanità-Italian National Institute of Health , Viale Regina Elena 299, 00161 Rome, Italy.
Francesco
http://orcid.org/0000-0003-3454-7947
F
Cubadda
biofortification; food; human health; in vitro simulated digestion; selenium; speciation