Abstract

The benefits of microalgae are due to the promising sources of pigments influencing  researchers to focus on optimizing the culture conditions for the high-yield pigment of microalgae culture. However, conventional procedures to determine microalgae pigments required a large sample volume and toxic chemicals. Due to the drawback of conventional procedures for determining the pigment of microalgae, this research aims to develop a new UV-visible spectrophotometry method using the Remote Diffuse Reflectance Accessory (RDRA) equipped with a UV-visible spectrophotometer for assessment of the total carotenoid content in green microalgae, Scenedesmus armatus. Using an optimal preparation of S. armatus on the Whatman GF/C™ glass microfiber (GF/C™) filter and scanning UV-visible spectra using RDRA, the characteristic peak of carotenoid at 480 nm demonstrates good analytical characteristics. It exhibits a strong linear relationship with cell concentrations ranging from 2-20´ 10⁷cells/mL (R² = 0.9884). The developed method yields a total carotenoid content of 2.16±0.58  ng/10⁴ cells for S. armatus. A paired t-test at a 95% confidence level indicates no significant difference (P≥0.05) between total carotenoid content obtained using the developed method and a conventional method (1.96±0.24 ng/10⁴ cells). In summary, the developed method shows promise for estimating total carotenoid content in green microalgae. Furthermore, the developed method offers advantages over the conventional method by reducing sample processing time and eliminating the need for hazardous reagents and a large volume of samples.

Keywords: Total Carotenoid Content, Microalgae, UV-visible Spectrophotometry