【Molecular formula】:C9H11NO3
【Molecular weight】: 181.19
【Properties】Colorless or white crystals, or white crystalline powder (from starch or rice), or brownish yellow (from molasses); almost tasteless, odorless, with special taste and sour taste. When heated to 160°C, it melts and separates out water molecules, and decomposes at 224~225°C. The aqueous solution is acidic, and the pH value of the saturated aqueous solution is about 3.2. Insoluble in water (0.72g/100ml, 20℃; 6.66g/100ml, 80℃).