The chemistry of mucin glycoprotein in swiftlet (Aerodramus fuciphagus) edible bird's nest

• Main Author: Shim, Eric Kian Shiun
• Other Authors: Alessandra Bonanni
• Format: Theses and Dissertations
• Language: English
• Published: 2019
• Subjects: DRNTU::Science::Chemistry
• Online Access: https://hdl.handle.net/10356/89891; http://hdl.handle.net/10220/47738
• Institution: Nanyang Technological University

The chemistry of mucin glycoprotein in edible bird’s nest (EBN), an esteemed delicacy and broad-spectrum supplement, produced by swiftlet Aerodramus fuciphagus has been explored in this thesis. In the first part of the project, the use of Raman microspectroscopy and thermal analysis tools (thermogravimetry, differential thermogravimetry, and differential scanning calorimetry) has provided new insights into the understanding of the properties of EBN mucin glycoprotein. The unique Raman spectrum shows characteristic bands of both protein and carbohydrate, justifying that EBN is a mucin glycoprotein, while the unique thermal analysis curves show the moisture content, thermal decomposition pattern, and ceramic ash content of EBN. Adulteration of EBN will give rise to a different Raman spectrum or thermal analysis curve, and thus the unique fingerprinting can be used to authenticate EBN samples. Overall, these analytical tools show high potential as rapid, simple, and label-free techniques to contend with the rampant adulteration of EBN. In the second part of the project, the molecular basis and chemistry behind the color of the more desirable red EBN or ‘blood’ nest that has been a puzzle for a long time have been investigated. Through the qualitative and quantitative analysis by Raman microspectroscopy, enzyme-linked immunosorbent assay, and UV-visible absorption spectroscopy, the nitration of protein tyrosine, which is recognized as ubiquitous in several diseases, to produce 3-nitrotyrosyl residue in mucin glycoprotein is found to be the real cause of the red coloration. The discovery of the underlying mechanism is useful when it comes to achieving a holistic evaluation of the benefits and values of EBN, and the findings could have refined the putative benefits of red EBN, which might have been touted for centuries.