In vitro study of antioxidant, antidiabetic, and antibacterial activity of orange (Citrus sinensis) and jade lemon (Citrus limon) peels essentials oils

Abstract Oranges and jade lemons belong to the citrus genus that grows in various parts of the world. Citrus flavor plays an important role in the global market and is commonly used in various industries. In this research, the biological activity of orange and lemon peel essential oils (EO) will be studied, i.e. antioxidant, antidiabetic and antibacterial. Characterization of the chemical compounds was also carried out using Fourier transform infrared spectroscopy (FTIR) and Gas chromatography-mass spectrometry (GC-MS) analysis. The analysis results show that the antioxidant activity of jade lemon using ß-carotene bleaching assay method is higher than orange, as of 34.81% and 14.32%, respectively. The antioxidants using the DPPH method show that both samples had low activity with IC50> 2000 ppm. The antidiabetic activity test using α-glucosidase inhibitory assay method showed that orange and jade lemon had good activity with results of 89.7 and 89.0%, respectively. The total phenolic content of orange and jade lemon using the Folin-Ciocalteau method was 182.7 mg gAE/g and 433.3 mg GAE/g, respectively. Antibacterial assay against Staphylococcus aureus showed that jade lemon had greater activity, as of 14.53 mm, while jade lemon had activity of 9.06 mm. Analysis of chemical compounds using GC-MS shows that jade lemon and orange have the largest composition of d-limonene compounds, as of 80.27% and 98.99%, respectively. The results of this research show that peel from orange and jade lemon essential oils has potential as a natural antimicrobial and antidiabetic for application in various food, cosmetic and pharmaceutical industries.