Comparative Study of the Effects of Conservation Methods on Herbal Plants

This study aimed to compare the effects of different conservation methods on the biochemical quality and antioxidant activity of mint, celery, parsley, and laurel. The plants were subjected to oven-drying at two temperatures (30 and 50°C), microwave drying at different powers (100, 300 and 600W), refrigeration for 24 hours, and freezing for 24 hours, 7 days and 40 days). The moisture content and dry weight were measured for each method. The total phenolic content, flavonoids level, and antioxidant activity were evaluated in fresh and dried plants. This study revealed a significant relationship between temperatures, time of conservation, species and phytochemical content. The results showed that each practical method can be ideal for each studied plant separately. Microwave drying at 300 and 600W resulted in increased TPC and TFC in mint and celery. Freezing for more than seven days led to a significant decrease in the TPC and TFC in all the plants except for the laurel. The findings could help researchers and practitioners choose the most appropriate drying method for each plant, to optimize the plant's antioxidant properties and economic value.