Color and antibacterial activity of annatto extracts at various pH of distilled
water solvent and extraction temperature
Annato (Bixa orrelana L.) has been renowned as a tropical plant rich in carotenoid pigments such as nonpolar bixin and polar norbixin. This study was aimed to obtain natural colorant and antimicrobials from annatto extracts. The extraction was carried out by maceration for 10 mins using distilled water as the extraction solvent at various pH and extraction temperatures. The variations of solvent pH used in this research were 4, 7, and 9, while that of extraction temperatures were 70, 80, and 90oC. The potential of annatto extract as an antimicrobial agent was tested by analyzing the extract's ability to inhibit pathogens and its phytochemical compounds. Escherichia coli and Staphylococcus aureus were used as the pathogenic bacteria by using the agar diffusion method. The color of annatto extracts was measured using Munsel Chard to determine the level of hue (color), value (brightness), and chroma (intensity), as well as maximum absorbance. The results showed that all extracts have the potential to inhibit E. coli and S aureus (weak-moderate). The observed annatto extracts had different color intensities as indicated by the hue, value, and chroma and a maximum absorbance at a wavelength of 400 nm.