Biological active substances retained during the spruce tree foliage storage process | Bioloģiski aktīvo savienojumu saglabāšanās egles zaleņa uzglabāšanas procesā

The aim of the investigation is to evaluate storing spruce tree foliage (needles and non-lignified small branches), together with branches, in piles at least 3 m high and no less than 4 m in width, to increase the possibility of obtaining biologically active substances and other extractives, for example organic acids, essential oils, chlorophyll derivatives and polyprenols. The piles were created during 2 days aft er tree felling in February, the end of March, July and October and stored for 90 to 129 days. The tree foliage samples were collected for analysis at the start day and then 5 times in intervals of 10 to 20 days. The amount of extractives and above mentioned biologically active substances was determined using standard analytical methods, and the results were calculated on a dry matter basis. The amount of essential oils was determined by hydrodistillation method using Dean-Stark apparatus. Summary extractives were obtained in a firm Buchi Extraction Unit B-811 LSV with non-polar solvent ''Nefraze'' (boiling temperature 80-120 deg C) used for tree foliage extractives production on an industrial scale. The amount of organic acids was determined by separating the summary extractives using saponification with sodium hydroxide water solution, followed by water solution acidification. Polyprenols concentrate was obtained from lipid parts after saponification with following column chromatography to isolate pure polyprenols. Each analysis was repeated at least 3 times and the results averaged. The results showed that 91-94% of total (summary) extractives, 68-72% of essential oils, 92-97% of organic acids, 40-55% chlorophyll derivatives and 60-69% of polyprenols remained in the tree foliage after 3 months of storage in piles. For the foliage piled in October the loss of active substances was smaller than in the summer (Table 1 and Table 2). The results indicate that tree foliage is usable for the production of polyprenols, chlorophyll derivatives, essential oils and organic acids when stored in piles for two months, and for essential oils and organic acids production when stored more than 2 months.