莲藕片汽蒸加工工艺及其挥发性风味物质变化研究

以莲藕为对象，采用汽蒸加工方式处理制成食用莲藕片。在单因素实验基础上，通过正交试验优化，探讨莲藕片汽蒸最佳加工工艺。并采用固相微萃取-气质联用技术，分析汽蒸加工处理过程前后挥发性风味物质变化。结果表明:在电磁炉功率为1400 W、莲藕切片厚度为4 mm的条件下汽蒸16 min，汽蒸莲藕片的感官评分为89.08，色差为9.85，硬度为555.57 g，此时莲藕片呈淡黄色，藕片肉质脆嫩，咀嚼性较好，具有藕香味。SPME-GC-MS鉴定出新鲜、汽蒸莲藕片中的挥发性风味物质分别为45、42种，二者共有28种化合物。莲藕中主要风味物质有壬醛、癸醛等醛类物质，此外还有柠檬烯、棕榈酸乙酯、辛醇、1-壬醇、香叶基丙酮等，这些风味物质使莲藕片呈现不同的风味特征。经过汽蒸过程后，醛类、杂环类及含氮化合物相对含量增加，酯类、醇类、酚类和酸类含量减少，酮类、醚类、烃类含量无明显变化。该研究结果可以为莲藕挥发性风味分析及莲藕加工工业提供一定的理论依据。

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.