Dissertation/Thesis Abstract

Bovine Oligosaccharide Diversity: A Physical and Chemical Process for Separation of Oligosaccharides from Bovine Colostrum and Milk
by Yeung, Henry, M.S., University of California, Davis, 2012, 68; 1519822
Abstract (Summary)

The fundamental importance of breastfeeding has been recognized for centuries before the concept of nutrition beyond caloric intake. Breastfeeding was established to increase the survival of offspring. Since the development of basic chromatography instruments, macro and micro nutrient content of breast milk has been annotated for its biological role in improving the offspring's health. There have been very few studies examining the bioactive glycated components of breast milk due to the lack of methods and sensitivity of analytical instruments. However, with the development of high throughput mass spectrometry and nano-chip high pressure liquid chromatography with high sensitivity, the field of glycobiology and lactation quickly matured. Previously, much effort has been placed into diagnosing the glycated molecules in human milk. Upon understanding functions of human milk oligosaccharides in vitro, substitutes for human-like bioactive glycated molecules have been discovered in bovine milk. Previously, human milk oligosaccharides had been extracted in gram quantities by our collaborators. This dissertation aimed to understand the physical and chemical processes involved with the extraction of oligosaccharides. Initially, the biological role, chemical composition, and methods of bovine oligosaccharide extractions were reviewed. The relative abundance of bovine oligosaccharides were examined using matrix assisted laser desorption ionization chromatography and nano-chip high performance liquid chromatography paired with time-of-flight mass spectrometry in order to identify the changes in oligosaccharide composition through lactation. Results showed that anionic oligosaccharides with sialic acid residues occupied a majority of oligosaccharides found in bovine milk; afterwards, neutral oligosaccharides slowly became the dominant free glycans in bovine milk due to either the decrease in acidic oligosaccharides or increase in neutral oligosaccharides. Method development for milligram quantity of bovine milk oligosaccharides was carried out. Early bovine colostrum was used for the oligosaccharides extraction. Similar structural profiles were obtained when the oligosaccharides were analyzed using methods identical to the previous analysis examining oligosaccharides as lactation progressed. The results point out that oligosaccharides are the dominant carbohydrates in human milk, other than lactose. In bovine, a tenfold decrease in oligosaccharide quantity was obtained. This thesis also showed a chemical method in which samples could be extracted in mass quantity for future in vivo studies.

Indexing (document details)
Advisor: German, J. Bruce
Commitee: Lebrilla, Carlito B., Mills, David A.
School: University of California, Davis
Department: Nutritional Biology
School Location: United States -- California
Source: MAI 51/03M(E), Masters Abstracts International
Subjects: Food Science, Analytical chemistry, Nutrition
Keywords: BMO, HPLC-Chip/MS, Human milk, Lactation, MALDI-FT ICR MS, Oligosaccharide
Publication Number: 1519822
ISBN: 978-1-267-66361-0
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