Steam Processing Technology of Lotus Root Slices and the Changes of Its Volatile Flavoring Substances

Based on single factor experiment and orthogonal experiment, the optimum processing technology of steaming lotus root slices were discussed. The changes of volatile flavor substances before and after steam treatment was analyzed by solid phase micro extraction-GC. The results showed that sensory scores of steam lotus root slices was 89.08, color difference was 9.85 and hardness was 555.57 g under the condition of 1400 W power, 4 mm thickness of lotus root slice and steam time 16 min. 45 and 42 volatile flavor compounds were identified by SPME-GC-MS in fresh and steamed lotus root slices. There were 28 compounds in common. The main flavor substances in lotus root were nonanal, decanal and other aldehyde substances, in addition, there were limonene, ethyl palmitate, octanol, 1-nonanol, vanillin acetone and so on, these flavor substances made lotus root slices showed different flavor characteristics. After steaming, the relative contents of aldehydes, heterocycles and nitrogen-containing compounds increased, the contents of esters, alcohols, phenols and acids decreased, and the contents of ketones, ethers and hydrocarbons did not change significantly. The results would provide a theoretical basis for the analysis of lotus root volatile flavor substances and lotus root processing industry.