Bioaccessibility and prebiotic effect of apple pomace: A promising new functional ingredient

Apple pomace (AP) is an underutilized bio-residue of the fruit processing industry with outstanding potential for conversion into bio-based ingredients. To assess its potential as a functional ingredient, a comparative in vitro digestion study (focusing phenolic bioaccessibility and prebiotic activity) was conducted using AP and its hydroethanolic extract (HE_AP). AP presented high concentrations of dietary fiber, organic acids, unsaturated fatty acids, and phenolic compounds, including both free and bound forms. Bioaccessibility studies demonstrated a dual release profile: HE_AP enabled a rapid release of phenolic compounds in the upper gastrointestinal tract (phenolics after digestion 364 ± 10 mg/100 g dw); whole AP ensured a gradual and sustained release of bioactive metabolites in the colon (64 ± 1 mg/100 g dw). Likewise, AP effectively promoted the growth of beneficial probiotic strains ( Lactobacillus and Bifidobacterium ), demonstrating its potential as a multifunctional ingredient to support gut health. These results promote the incorporation of AP into innovative and sustainable food and nutraceutical formulations.