Impact of In vitro Gastrointestinal Digestion on the Chemical Composition and Prebiotic Potential of Coffee Silverskin

The growing interest in prebiotic ingredients has led to the valorization of agri-food by-products, such as coffee silverskin, known for its richness in dietary fiber and health-promoting compounds. This study evaluated the impact of in vitro simulation of gastrointestinal digestion on the chemical composition (carbohydrates, caffeine, and chlorogenic acids) and prebiotic potential (probiotic growth, organic acid production, pH, and antioxidant activity) of milled coffee silverskin. The results show stability of polysaccharides during digestion, while caffeine and 5-caffeoylquinic acid were partially released into the bioaccessible fraction. The incubation of digested sample (DS) and the control (CS) with Lacticaseibacillus paracasei subsp. paracasei and Lactiplantibacillus plantarum subsp. plantarum resulted in probiotic growth, an increase in acetic acid production, and pH decrease. Following incubation, the cell-free supernatants of the DS and CS exhibited greater antioxidant activity compared to the negative control, glucose, and fructooligosaccharides. This study shows the functional potential of the whole silverskin due to its prebiotic and antioxidant properties.