Process Optimization and Quality Analysis of Shelf-life Extension for Passion Fruit Preserved Peel by Multi-factor Synergistic Regulation via Hurdle Technology

In order to improve the utilization rate of passion fruit peel resources and solve the technical bottleneck of short shelf life of candied fruits, the peel of passion fruit was used as the raw material, and three key factors of water activity (Aw), citric acid addition and sugar addition were synergistically regulated by using the hurdle technology to optimize the processing technology. By taking the shelf life as the core index, the range of parameters was screened through the single factor test, and the process parameters were optimized by the orthogonal test. Then, the best process scheme was determined by using the sensory evaluation. The results indicated that the primary and secondary factors affecting the shelf life of candied passion fruits were the citric acid addition＞water activity＞sugar addition. The optimal process combination was A₂B₂C₃ (Aw of 0.5−0.55, citric acid of 0.8%, sugar of 14%). The verification result through the accelerated tests at 45℃ and 35℃ showed that, the shelf life of the passion fruit preserves at 25℃ was predicted to extend up to 833 days. After 300 days of storage at 25℃, the microbial index of the product met the requirements of GB/T 10782−2021 General Standard for the Quality of Preserved Fruits, with the sensory score of 88.33. This study provided a reliable technological pathway for the high-value utilization of passion fruit peels.