Changes of free and nanoencapsulated hydroxycinnamic acids from green coffee added to different food products during processing and in vitro enzymatic digestion

Abstract An aqueous extract was derived from green coffee beans. To increase the concentration of hydroxycinnamic acids (HCAs) the extract was purified by centrifugal partition chromatography (CPC). The purified extract was used to form inclusion complexes of HCAs with β-cyclodextrin (β-CD). HCAs were used to enrich six food products: cookies, bread, caramel cottage, mushroom and meat stuffing and nutty filling. Each product was prepared in five options: control, supplemented with 1% of HCAs from GCE, supplemented with 5% of protein hydrolysate, supplemented with both 1% of HCAs from GCE and 5% of protein hydrolysate, and supplemented with 1% of HCAs in the form of an inclusion complex. The concentration of HCAs and total polyphenols in the obtained products was analyzed by the LC/MS n method and the products were then hydrolyzed by digestive enzymes: α-amylase, pepsin, trypsin, chymotrypsin and amyloglucosidase and again analyzed for HCAs and total polyphenol content. Bioaccessibility of HCAs and total polyphenols found as an unbound form in the supplemented foods was reduced by processing and further by enzymatic hydrolysis. Furthermore the addition of protein hydrolysate led to a significant decrease of HCAs and total polyphenol bioaccessibility. Inclusion of HCAs into β-cyclodextrin before supplementation into food led to the increase of their bioaccessibility both after food processing and further enzymatic hydrolysis.