Date Available
4-1-2021
Year of Publication
2021
Degree Name
Master of Science (MS)
Document Type
Master's Thesis
College
Agriculture, Food and Environment
Department/School/Program
Animal and Food Sciences
First Advisor
Dr. Rachel R. Schendel
Second Advisor
Dr. William Boatright
Abstract
Arabinoxylan (AX) is a major structural polysaccharide found in the cell walls of monocots such as cereal grains and pasture grasses. The variety of AX structural components and substitution patterns contribute to AX structural diversity between different monocot species as well as plant tissues.
The rumen is the first digestion site of masticated food material in cattle and provides 70% of energy to host through fermentation of forage. There are many species of pasture grasses that act as a forage source. Differences in AX structure found in these pasture grasses may impact rumen microbial fermentation. Understanding the AX structure of different pasture grasses can elucidate how different AX structures can impact rumen microbial fermentation.
The objectives of this research were to develop a high-performance anion-exchange chromatography (HPAEC-PAD) method to rapidly quantify AX oligosaccharides (or AXOS) released via endoxylanase digestion and characterize the AX structure in four cool-season pasture grasses from central KY (timothy, perennial rye, tall fescue, and bluegrass). Quantification of AXOS enabled the comparison of AX structural profiles between grass materials.
An HPAEC-PAD method was developed and validated for xylanase-released AXOS using analytical parameters concentration range (CR), limit of detection (LOD), limit of quantification (LOQ), retention time (tR HPAEC), and relative response factor (RRF). Perennial rye tended to have greater amounts of AXOS compared to the other pasture grasses. 3X was released by endoxylanase in greatest amounts compared to other AXOS (significant difference varies). In addition, the cell wall monosaccharide and ester-linked hydroxycinnamic acid (HCA) contents were profiled in each cool-season pasture grass.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2021.032
Funding Information
This study was supported by the Sustainable Forage-Based Production for the Mid-South Transition Zone, ARS Project # 5042-21000-002-00D from the United States Department of Agriculture in 2018.
Recommended Citation
Joyce, Glenna Erin, "ARABINOXYLAN STRUCTURAL PROFILING OF COOL-SEASON PASTURE GRASSES VIA HIGH-PERFORMANCE ANION-EXCHANGE CHROMATOGRAPHY WITH PULSED AMPEROMETRIC DETECTION (HPAEC-PAD) ANALYSIS OF ENDOXYLANASE DIGESTS" (2021). Theses and Dissertations--Animal and Food Sciences. 124.
https://uknowledge.uky.edu/animalsci_etds/124
Included in
Animal Sciences Commons, Food Chemistry Commons, Plant Sciences Commons, Structural Biology Commons