论文以上海青和菜心作为研究对象，探究了叶菜在热烫加工、冷链贮藏和微波复热过程中亚硝酸盐含量、硝酸盐含量、菌落总数、维生素C（Vc）含量等指标的变化。结果表明：因亚硝酸盐易溶于水，热烫处理能有效降低叶菜中的亚硝酸盐含量；冷藏过程前期叶菜中的Vc协助抑制亚硝酸盐增长，而冷藏后期随着Vc的消耗和微生物增长，亚硝酸盐含量逐渐增加，上海青和菜心在4 ℃分别冷藏5 d和4 d后亚硝酸盐含量仍能维持在4 mg/kg的安全标准内，而10 ℃冷藏的只能保证2 d内的安全性；微波复热过程由于水分散失导致硝酸盐和亚硝酸盐的浓度增加，因此复热过程应避免大面积敞口加热。本文探索了热烫叶菜在冷链储运及微波复热过程中亚硝酸盐的累积机理，为其应用于冷链盒饭提供理论依据。

The Chinese cabbage (CC) and Chinese flowering cabbage (CFC) were used as the study objects here, and the changes in the nitrite content, nitrate content, total bacterial count, and vitamin C (Vc) content of green leafy vegetables during blanching, cold-chain storage, and microwave-reheating processes were explored. The results showed that the blanching process significantly reduced the nitrite content, because nitrite is readily soluble in water. At the beginning of cold storage, Vc content in the leafy vegetables helped inhibit increases in nitrite content; however, during the late stage of cold storage, nitrite content increased gradually along with the bacterial growth Vc consumption. Additionally, when CC and CFC were stored at 4 ℃ for five days and four days, respectively, the nitrite content remained below the safety limit of 4 mg/kg, whereas for a storage at 10 ℃, the food safety could only be ensured for two days. During the microwave-reheating process, nitrate and nitrite concentrations increased as water evaporated, indicating that uncovered reheating should be avoided. This study investigated the mechanism associated with nitrite accumulation during the cold-chain storage and microwave reheating of blanched green leafy vegetables, and provides a theoretical foundation for the application of blanched green leafy vegetables in cold-chain-packed meals.

省级现代农业（农产品无损检测及精深加工）产业技术研发中心建设项目资助（B2152840）