Time-dependent changes in quality of Apiaceae spices under synergistic effects of ultraviolet radiation and hermetic storage

Abstract

This study investigates the combined effects of ultraviolet radiation (UV-C) and hermetic storage on the quality of Apiaceae spices intended for consumption after long-term storage. Anise, fennel, caraway, and cumin seeds were exposed to UV radiation for 0 (control) and 25 min of UV-C. Subsequently, the seeds were packed into jute and multilayers of polyethylene hermetic bags (120, 150, and 160 μm with an antifungal coating) and stored in a naturally aerated storage room for 12 months. During the storage period, the ambient conditions ranged from 17.2 °C to 30.5 °C and from 59.3 % to 62.8 % RH. While the jute bags maintained the ambient conditions, the hermetic bags had significantly (P< 0.05) decreased temperature and relative humidity, depending on the packaging type and UV-C treatment. The seed moisture content increased significantly (P< 0.05) during storage. The increase percentage reached (20.5–24 %) in jute bags containing untreated seeds, whereas the 150 μm and antifungal bags containing UV-treated seeds had the lowest increase percentage (0.3–4.0 %). By the end of the storage period, the hermetic bags containing fennel-treated seeds had the highest significant (CO2/O2) ratio of 163.8. UV-C efficiently suppressed microorganisms and insect infestation, particularly in seeds stored in the 150 μm and antifungal bags. After 6 months of storage, the jute bags had 465–578 insects/kg. The results show that hermetic conditions maintained the phenolic content and antioxidants of Apiaceae spices, particularly with UV-treated seed. Based on the findings, pretreating Apiaceae seeds with UV-C sterilization is recommended prior to storage in hermetic bags. This approach is expected to accelerate the start of optimal hermetic conditions, thereby enhancing seed quality.