Experimental investigation on food science : melamine detection & fish freshness testing

• Main Author: Lim, Sheng Jie
• Other Authors: Du Hejun
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering; DRNTU::Science
• Online Access: http://hdl.handle.net/10356/60473
• Institution: Nanyang Technological University

Areas of interest in food science such as food composition, toxic detection, etc., are some of the hot topics in research over the years. In this project, melamine solutions were deposited on different substrates and detected using surface enhanced Raman spectroscopy (SERS). The lowest limit of detection (LOD) obtained of was 10ppm using ZnO nanorods (ZnO-NR) substrate. ZnO-NR were randomly deposited on glass surface, forming hotspots for SERS enhancement. Another substrate, with ZnO-NR coated with silver nanoparticles (Ag-NP), was proven to be unstable for SERS during exposure to laser. The usage of ZnO-NR coated with gold nanoparticles (Au-NP) showed some enhancement despite the fluorescence effect when using 532nm laser source. Apart from food detection, degradation of fish meat with time was studied using impedance spectroscopy. Salmon meat was chosen as the typical sample to be studied. In this work, the rate of change of impedance was significantly large at the range around -120,000Z/t during the second stage of degradation. This indicates the potential of research on this topic on fish meat.