Production of selenium-containing extracts from vegetable materials
The effect of proteolytic and cytolytic enzymes, as well as extraction time, on the efficiency of selenium extraction from vegetable materials was evaluated. The materials containing selenium to be extracted were Chinese lettuce (Brassica rapa) of pak-choi variety and amaranth (Amaranthus caudatus L.) of Kharkovskiy variety, both undergone selenium enrichment via agrochemical cultivation. A single water solution of DistizymProtacid Extra (proteolytic) and Viscostar (cytolytic) enzymes served as the extracting agent. Said solution was introduced into samples, with the exception of two control samples, in such quantities that the dosage of non-diluted enzymes was 1 µl each enzyme to 1 g sample. Accounting for the dilution, the resulting dosage was 1 part water solution to 12 parts vegetable material. Extraction time amounted to 24 hours. The temperature of extraction was either 45°C or 55°C. Selenium content in the extracts obtained was determined according to GOST R 53182–2008. It was found that the amount of dry matter in extracts became larger as extraction process continued. The maximum of dry matter content in pakchoi lettuce and amaranth extracts was achieved at non-zero enzyme dosage (1 µl per 1 g) and the extraction temperature of 55°C and was equal to 7.40 g?100 cm–3and 2.95 g?100 cm?3 dry matter, respectively. Selenium content in all extracts amounted to 257.3 µg?dm?3 at 45°C and 284.9 µg?dm?3 at 55°C; in amaranth extracts 325.8 µg?dm–3 (45°C) and 347.0 µg?dm?3 (55°C). The results obtained may be further applied to preparation of food adjuncts and functional foods.