Comparative assessment of citrus spp. in phytochemical analysis, antibacterial activity and DPPH scavenging analysis / Norsyazwani Sulaiman

The Citrus spp. is the member of family Rutaceae, widely distributed in the tropical and subtropical countries. The rapid growth of the processing industry is demanding some natural antibacterial agents. Therefore, this study aims to determine the percentage yield of the Citrus spp. peel extracts using 95% ethanol, analysed phytochemical analysis as well as determine antibacterial and antioxidant activities. The peel extracts were prepared in 95% ethanol using rotary evaporator. The peel extracts of Citrus spp. were screened for the presence of biological compounds such as alkaloids, flavonoids, saponins, tannins and steroids. For the determination of the antibacterial activity of Citrus spp., the disc diffusion assay was used against Staphylococcus aureus (S. aureus) and Staphylococcus epidermidis (S. epidermidis). The Citrus spp. peel extracts were determined for it antioxidant properties using DPPH free radical scavenging activity. The result of this study showed C. hystrix had the highest percentage yield of crude extracts at 5.03% while the lowest was C. aurantifolia which was only 0.44%. The yield of crude extract of C. microcarpa was 0.76%. The phytochemical screening showed that the Citrus spp. have positive results regarding alkaloids, flavonoids, saponins, tannins and steroids. For antibacterial activity, Gram-positive bacteria of S. aureus and S. epidermidis were susceptible responds to the C. hystrix at concentration of 400 000 μg/ml. However, both bacteria were considered as intermediate response towards all combinations of Citrus spp. IC50 value of DPPH free radical scavenging assay for C. microcarpa was 0.593 μg/ml revealed that C. microcarpa had the highest antioxidant compared to the C. hystrix and C. aurantifolia. As conclusion, Citrus spp. peels extract can be used efficiently as an alternative for the production of potential antibacterial agent and beneficial to the food industry.