Extraction of Bioactive Substances from Medicinal Plants with Whey: Selecting Optimal Parameters

Due to its natural chemical composition, whey can have both a positive effect on the human body and cause significant harm to the environment. It is rich in organic substances, which creates an additional organic burden on nature. However, whey has good prospects for the food industry as an extractant for the production of plant extracts and biologically active substances. The present research objective was to select optimal parameters for obtaining flavonoids from plant extracts using an unconventional type of extractant, i.e., whey. The study featured whey as an extractant and mixes of medicinal herbs. The resulting extracts were tested for the content of flavonoid compounds by thin-layer chromatography. The antioxidant activity was assessed using the spectrophotometric method. The extraction variables included temperature, extraction time, material-to-extractant ratio, and composition of herbal mixes. The extraction time ranged from 1 to 5 h at 90 ± 1℃. The maximal antioxidant activity belonged to the samples containing 7.5–12.5 g herbal mix and 450 ml whey. The optimal extraction time was 3 h. The content of flavonoids in the plant extracts was comparable and did not depend on the extraction time. Extraction time proved to be the key parameter to intensify the process of flavonoid extraction from plant raw materials. Therefore, the choice was made according to the shortest time with comparable values of flavonoids and the maximal level of antioxidant activity.