Study on the chemical behaviour of Bisphenol S during the in vitro gastrointestinal digestion and its bioaccessibility

•In vitro assessment of the bioaccessibility of Bisphenol S after human ingestion.•The pHs and enzymes reduce the bioaccessibility of Bisphenol S.•The food matrix (soy drink) slightly reduces the bioaccessibility of Bisphenol S.•BPS bioaccessibility ranged from 50 to 80% after digestion at the intestinal phase.•An analytical method to analyze Bisphenol S and their degradation products. This study evaluated the chemical behaviour of Bisphenol S (BPS) and determined its bioaccessibility after human ingestion using a standardised in vitro gastrointestinal digestion protocol and an analytical method based on high-pressure liquid chromatography coupled with a photodiode array and tandem mass spectrometry. The effects of different factors such as gastric pH, enzymes, and food matrix on the solubility and chemical stability of BPS were studied to evaluate their contribution to its bioaccessibility. The results highlighted that BPS was available at the end of the digestion process in the range of 50–80%, and was susceptible to absorption at the intestinal level. The effect of pH was not significant as a single factor. The presence of enzymes slightly decreased the bioaccessibility of BPS in the intestinal phase with gastric pH increase. Additionally, a soy drink reduced BPS bioaccessibility by up to 5% after oral intake. Finally, a few BPS degradation products were found in non-bioaccessible fractions at different pH values.