The objective of the research study was to determine the changes in the content of nitrates (V) in fresh spice herb species: basil (Ocimum basilicum L.) ‘Wala’ cultivar, summer savory (Satureja hortensis L.), tarragon (Artemisia dracunculus L.), lovage (Levisticum officinale L.), oregano (Origanum vulgare L.), and thyme (Thymus vulgaris L.) after their preservation with the use of two methods: drying under the controlled conditions at 30-35 °C and freezing at -25 °C. The content of nitrates (V) was determined colorimetrically in the fresh and preserved plant material, as well as after storage (60, 120, 180, and 240 days of storage). It was found that the fresh basil and oregano were characterized by the significantly highest content of nitrates (V) and the fresh thyme by the lowest content of NO3. Immediately after freezing the content of nitrates (V) decreased in all herb spice species. A similar relationship was found in the basil, oregano, and lovage after drying. However, an increase was reported in the content of NO3 in the dried summer savory and thyme. While storing the frozen and dried materials, the content of nitrates (V) systematically increased.
spice herbs, nitrates (V), drying, freezing, storage