Phytochemical Profiling and Antimicrobial Efficacy of Peanut Shell and Skin Extracts

Bioactive substances such as flavanols and phytosterols, which are plentiful in leguminous plants like peanuts, help protect against various diseases. Commonly known as peanuts or groundnuts, Arachis hypogaea is a significant source of proteins and phytochemicals. Additionally, peanuts are rich in antioxidants that enhance health by neutralizing free radicals. The versatile use of peanut skin, particularly known for its high content of flavonoids, stilbenes (including resveratrol), and other phenolic compounds, has been the focus of extensive research over the years. This study aimed to examine the antibacterial activity and phytochemical composition of extracts derived from peanut shells and skins. The extraction was performed using three solvents: water, ethyl acetate, and methanol. A mixture of 50 ml of each solvent with 5 g of powdered skin and shell was shaken for 72 hours. Following filtration, the extracts were utilized for further analysis. Phytochemical screening revealed that most bioactive substances, including tannins, phenolphthaleins, saponins, flavonoids, terpenoids, and glycosides, were present in both the shell and skin extracts, except for coumarins and glycosides, which were absent in the shell extract. The methanolic extract of peanut skin exhibited significant antibacterial activity against opportunistic pathogens, notably Pseudomonas aeruginosa and Staphylococcus aureus. When evaluated against P. aeruginosa, the skin extracts in distilled water, ethyl acetate, and methanol demonstrated zones of inhibition measuring 8 mm, 9 mm, and 10 mm, respectively. The high concentration of bioactive compounds in the skin extract is responsible for its antibacterial properties. The findings highlight the potential of peanut skin as a rich source of bioactive compounds and antimicrobial agents, suggesting its application in developing natural antimicrobial formulations and contributing to the growing interest in environmentally friendly and sustainable solutions for antimicrobial research.