Quality change and shelf life prediction model of impregnating bayberry by vacuum combined with CaCl₂ and Vc treatment

Bayberry, a subtropical fruit with distinct Chinese characteristics, is highly nutritious but prone to spoilage during storage and transportation, resulting in a short shelf life. To improve its storage quality and extend the shelf life, this study investigated the effects of vacuum impregnation combined with CaCl₂ and ascorbic acid (Vc) treatments. The quality attributes of bayberry during storage were examined, and a shelf life prediction model was developed. The results demonstrated that the combined treatment effectively slowed down the decline in hardness, soluble solids, total phenols, and pectin content, inhibited the increase in decay rate and weight loss. Additionally, the treatment maintained color stability and reduced the activity of polygalacturonase and pectin methylesterase, thereby preserving the quality of bayberry during storage. Analysis of the pectin structure revealed that chelating pectin in treated bayberries retained a network structure with minor branching even at the end of storage, indicating minimal degradation. The structure of chelating pectin was found to be closely associated with bayberry hardness. Furthermore, the modified Gompertz model was applied to establish a shelf life prediction model for bayberry at storage temperatures of 2-25 ℃. The model demonstrated high accuracy, with the deviation and precision between measured and predicted values ranging from 0.998 to 1.004 and 1.009 to 1.014, respectively. The combined treatment of vacuum impregnation with CaCl₂ and Vc effectively preserved bayberry quality during storage, and the developed model accurately predicted shelf life within the specified temperature range.