Modern conservation methods of medicinal plant raw materials: variability of the content and stability of biologically active substances

Introduction. To preserve the maximum content of biologically active substances (BAS) in medicinal plant raw materials during storage, it is necessary to subject it to conservation. Modern methods of preservation are drying and freezing. However, in both cases, the content of BAS will vary due to various factors. Thus, it is necessary to research the choice of a priority conservation method to preserve the highest content of BAS in medicinal plant raw materials. Objective: to study the effect of freezing and drying of medicinal plant raw materials on the content of BAS. Material and methods. Fresh lingonberry fruits (Vaccinium vitis-idaea L.), collected on the territory of the Tver region during the fruiting period in 2020 and subjected to conservation. Determination of BAS content (ascorbic acid, organic acids, tannins, flavonoids, anthocyanins) in fruits was carried out according to the methods set out in pharmacopoeia monographs. Results. In the course of a comparative study of BAS, it was found that in frozen fruits the content of ascorbic acid, organic acids, flavonoids decreased by 7, 8 and 26%, respectively, and the content of tannins and anthocyanins even increased slightly. The drying conditions (natural and artificial drying) did not affect the content of BAS. A significant decrease in the content of ascorbic acid was observed in the dried fruits. During the storage of frozen fruits for 6 months, there was a tendency to decrease ascorbic acid and anthocyanins, the number of organic acids practically did not change. Data on the storage of dried fruits indicate the stabilization of the content of BAS after 3 months of storage. Conclusion. It is shown that freezing, as a conservation method, is the most preferable for preserving the content of BAS in the medicinal plant raw materials. The stability of BAS in frozen and dried fruits during storage has been studied. The recommended shelf life of frozen fruits is 6 months and of dried fruits is 12 months.