Bioaccessibility of polyphenols from plant-processing byproducts of black carrot (Daucus carota L.)

Plant processing by-products of black carrot represent an important disposal problem for the industry, however they are also promising sources of polyphenols, especially anthocyanins. The present study focused on the changes in polyphenols from black carrot, peel and pomace during in vitro gastrointestinal digestion. Total phenolic content (TPC), total monomeric anthocyanin content (TMAC) and total antioxidant capacity (TAC) were determined using spectrophotometric methods, whereas identification and quantification of polyphenols was carried out using UPLC-ESI-MSE and HPLC-DAD, respectively. TPC, TMAC and TAC significantly decreased (23–82%) as a result of in vitro gastrointestinal digestion. Nevertheless the amount of pomace anthocyanins released at all stages of in vitro gastrointestinal digestion was higher than black carrot anthocyanins, suggesting that pomace may be a better source of bioaccessible anthocyanins. Overall, the current study highlighted black carrot by-products as substantial sources of polyphenols, which may be used to enrich food products