In vitro digestion of selenium from selenium-enriched chicken

Selenium (Se) is an essential trace element important for several biological functions, such as thyroid hormone metabolism, anti-aging, and antioxidant protection. Even though reports on Se species in different food products are increasing, the scientific knowledge on the bioaccessible amount of Se species from these products is not as well known. In this work, Se-enriched chicken meat was digested by an in vitro model using human gastro-intestinal (GI) juices and different commercial enzymes. The aim of the study was to gain information on the bioaccessible amount of Se from meat after digestion by different relevant enzymes with the approach of replacing human liquids with commercial enzymes that could mimic the digestion in the human GI tract. The digestion with commercial enzymes such as pepsin, protease, and lipase resulted in highly variable extraction yield of Se in isotonic salt water (50-90 %). Se proteins were degraded into SeMet, while Se species with higher molecular mass were present in the extracts from human juices. The extraction yield using human juices was only about 70 % of Se from the meat, but Se in the extracts was normally distributed with a low standard deviation (4 %), indicating stability of the results from digested extract.