Analysis of pharmacognostical standardization, antioxidant capacity and separation of phytocompounds from five different vegetable peels using different solvents

Abstract

Vegetables are one of the most preferred food commodities and can be consumed either raw or as processed due to their health-promoting nutrients. In the present work, analysis of pharmacognostical standards, antioxidant capacity, and separation of phytocompounds through thin layer chromatography (TLC) from cabbage, cauliflower, pea, carrot, and potato peels were carried out. Microscopic analysis revealed the presence of wood fibers, trichomes, crystals, and annular xylem vessels in the vegetable peels. Physicochemical analysis showed that all the vegetable peel samples which were analysed have low (7.08%-10%) moisture content. The total ash content of vegetable peels varied in cauliflower peels (1.95±0.58) to the peels of pea (19.86±1.9). The content of acid insoluble ash varied from 1.46±0.63 to 3.09±0.59 in cauliflower and pea. Potato peel has the lowest water-soluble ash content (1.16±1.90) as compared to other peels. The highest pH value was found in the peels of pea (7), while the lowest pH was found in the peels of cabbage (4). Among all extracts, the petroleum ether extract has shown the greatest yield (5.6±0.45). The fluorescence analysis showed various colours like green, brown, pale green, and yellow under different chemical treatments. Different types of pri-secondary metabolites were detected in small, moderate, and high amounts and notified to provide numerous health benefits to humans. In case of DPPH assay, aqueous extract of cauliflower has shown the low value of IC50 (24.82 µg/ml) in comparison to standard, suggested the higher antioxidant activity of the extract. Among all the extracts, aqueous and methanol extracts of cauliflower have shown the better reducing and total antioxidant activity in comparison to standard. TLC profiling of methanolic extract of cabbage and cauliflower peels revealed the presence of different compounds of varying Rf values. Above results indicate that the food waste consists of valuable components and may be utilized as noticeable and cheap source in pharmaceuticals for the treatment of several life-threatening diseases.