关键词: 燕窝, 银耳, 红外光谱, 热分析, SEM

Abstract: In order to distinguish the chemical structure, thermal properties and microstructure between edible bird’s nest and tremella, the chemical functional groups of edible bird’s nest and tremella were analyzed with infrared spectrum （FTIR）, the first and the second derivatives as well as Norris first derivative of FTIR were studied, the thermal properties were analyzed with comprehensive thermal analyzer, and their surface microstructure were observed with SEM. The results showed that the main absorption position of infrared spectrum of edible bird’s nest was close to tremella while the absorption peak intensity are fairly different with that of edible bird’s nest being stronger. The absorption peaks of protein, amino acid, and the hydroxyl, methyl, and methylene of polysaccharide were observed at 3 431 and 2 922 cm^-1. The protein amide I band, II band, and III band stretching absorption peak were observed at 1 636, 1 448, 1 384 cm^-1. However, tremella had absorption peak of fat around 1 732 cm^-1. In the fingerprint region with a wave number less than 1 300 cm^-1, the first and the second derivatives and the Norris first derivative of edible bird’s nest and tremella showed great differences. Thermal weight loss curves and DSC curves betweenedible bird’s nest and tremella were significantly different. Thermal weight loss of bird’s nest was greater at 160~400 ℃, while that of tremella was greater at 250~400 ℃. There are distinct differences on microstructure ofedible bird’s nest and tremella. Obvious strip texture oriented in a certain direction can be seen on the surface of edible bird’s nest while considerable convex body accumulated on the surface of tremella. The results provided the basis to distinguish edible bird’s nest and tremella in spectral analysis and microstructure using integrated approaches.

Key words: edible bird's nest, tremella, infrared spectrum, thermal analysis, SEM