Improvement of physico‐chemical properties and phenolic compounds bioavailability by concentrating dietary fiber of peach ( Prunus persica ) juice by‐product

BACKGROUND This study aimed to concentrate dietary fiber (DF) from peach ( Prunus persica ) juice by‐product (PJBP), to improve its functional properties, and its polyphenols bioavailability. The dietary fiber concentrates (DFCs) were obtained from PJBP using water/ethanol treatments (100:0, 20:80, 50:50, 80:20, and 0:100, v/v) at 1:5 ratio (wet weight/solvent, w/v) for 5 and 20 min at 21 °C. RESULTS All treatments concentrated condensed tannins, total and insoluble DF, with the highest content found with 100% H 2 O treatment. The major polyphenols of DFC were 4‐ O ‐caffeoylquinic, chlorogenic, and 1,5‐di‐ O ‐caffeoylquinic acids. Water and oil retention capacity and maximum glucose diffusion rate were improved mainly with 100% H 2 O treatment. Healthy rats were fed with a standard diet supplemented with 8% of PJBP, DFC obtained with 100% H 2 O for 5 min, or DFC obtained with 20% EtOH for 5 min. Gastrointestinal digesta weight and viscosity were increased in animals supplemented with 100% H 2 O DFC. Moreover, the urinary excretion of polyphenol metabolites, mainly glucuronide and sulfate conjugates, was increased with this treatment, indicating a greater bioavailability of PJBP polyphenols, which was associated with an increased dietary fiber porosity. CONCLUSION Water treatment could be used to potentiate PJBP functional properties and polyphenols bioavailability. © 2017 Society of Chemical Industry