Investigation for the Antibacterial Activity of Five Citrus Fruits’ Peel Extracts

Abstract

Bacterial infections are very important problems of world population. Many countries have to pay large budgets dealing with these diseases. However, there were lots of studies currently reported that fruits and folk plants were rich sources of medicinal compounds those have high potential as antimicrobial agents for alternative treatments. In this study, fruit peels of five citrus fruits including Citrus maxima, Citrus reticulata Blanco, Citrus reticulata Blanco cv. Sainampueng, Citrus hystrix DC and Citrus aurantifolia were extracted by using four methods including boiling, maceration in absolute ethanol, blending of  fruit peels powder in water and blending of fresh fruit peels in water. The antibacterial activities of citrus fruits’ peels were evaluated using the agar disk diffusion method towards Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. The results showed that crude extracts of these five fruits’peels from ethanolic extraction had antibacterial activity to S. aureus and those using dry powder blending extraction had antibacterial activity to P. aeruginosa. No inhibition zone was found in all five extracts that used boiling extraction and fresh peel blending extraction.This study also showed that the activities of those extracts depended on many factors such as species of fruits, solvent, and the method of extraction. This preliminary study demonstrated that these citrus fruits’ peels contained some interesting levels of antibacterial components. Further study for the type and quantity of those important substances should be performed. This will lead to proper applications in pharmaceuticals or other antimicrobial products in future.