Composition of bound polyphenols from carrot dietary fiber and its in vivo and in vitro antioxidant activity

Qualitative analysis of bound polyphenols from carrot dietary fiber (CDF-PP) was performed by ultra-performance liquid chromatography equipped with an electrospray ionization and quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS/MS). Eleven organic acids, nine hydroxybenzoic acids and derivatives, six hydroxycinnamic acids and derivatives, four phenolic alcohols and derivatives, three flavonoids and derivatives, seven esters and derivatives, two other compounds, were detected by matching their retention times, secondary mass spectrometry fragment information with authentic standards or literature data. Furthermore, in vitro antioxidant activity was determined by different kinds of assays, including DPPH, ORAC, PSC, demonstrated that CDF-PP could scavenge radicals in a dose dependent manner. Moreover, CDF-PP exhibited significantly reactive oxygen species (ROS) scavenging activity in living Caenorhabditis elegans. To our knowledge, this is the first comprehensive research to investigate composition and in vitro/in vivo antioxidant activity of bound polyphenols in CDF, which implied that CDF-PP could be a promising source of antioxidants.