Quality Analysis and Shelf Life Prediction of Ningxia Cabbage during Storage after Precooling

Vacuum precooling and cold storage precooling were used to treat Ningxia cabbage. The precooling and storage experiments were carried out at 0,5 and 10℃,respectively. The weight loss rate,chlorophyll,color,and other quality indexes were measured during the storage period until it lost its edible value. A dynamic credit analysis model was established to predict its shelf life. The results showed that the lower the storage temperature was,the slower the change of quality index was. After vacuum precooling,the quality of cabbage was better than cold storage precooling. Vacuum precooling could effectively delay the decline of weight loss,chlorophyll,and color.0℃ was the best vacuum precooling and storage temperature for maintaining good sensory quality of cabbage in Ningxia. The dynamic analysis showed that the changes of weight loss rate,L^* value and a^* value are in accordance with the zero-order reaction kinetic model,and the changes of chlorophyll and b^* were suitable for the first order reaction kinetic model. The dynamic model established was verified to be effective and could be used to predict the shelf life of vegetable heart under the storage temperature of 0,5 and 10℃ for 21,12 and 9 d respectively.