Vanja Djukic
University of Guelph, Canada
Title: The effect of in vitro rumen digestion on polyphenol content and free radical scavenging activity of apple pomace
Biography
Biography: Vanja Djukic
Abstract
This project is part of a larger task pursuing the development of naturally produced, health-contributing, polyphenol-enriched milk products that are derived from byproduct plant matter from agricultural sources. Apple pomace (AP), an abundant agricultural by product in Canada has a high polyophenol content (1000-1415g gallic acid equivalent/100g dry weight). 17,36 The objective of this study is to evaluate the effects of in vitro rumen digestion on the total polyphenol content and free radical scavenging activity of AP. AP will be collected fresh and kept at -20°C until analysis. Rumen inoculum will be collected from a mature lactating cow and in vitro digestion will be performed for 24 and 48hr of digestion in an ANKOM RF Gas Production System as per manufacturer’s instructions.3 After digestion, the samples will be centrifuged at 26 940g and filtered through 0.2um polyethersulfone filters to remove bacterial cells.10 All samples (treated and untreated) will be freeze dried and ground, after which polyphenols will be extracted by solvent extraction (80% methanol at 21°C for 1hr).33 Fast Blue BB assay for total polyphenol quantification and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity assay will be performed on all samples in triplicate with 3 technical replicates to assess the extent of polyphenol degradation in the rumen33. The fraction of polyphenols remaining after in vitro digestion will be roughly representative of the amount available for absorption into the cow’s bloodstream and subsequently the mammary gland.