Carotenoid Profile of Freshwater Microalgae Mychonastes racemosus AUP1 and its Antioxidant properties

Abstract

Microalgae contain some active compounds that can be used for various purposes, such as carotenoids and high-value compounds with antioxidant capacity to be used as ingredients for food and pharmaceuticals This study aims to isolate microalgae from freshwater to produce carotenoid pigments. A green microalga was isolated from a local freshwater pond. Morphological observation and molecular analysis were performed to identify the microalgae. The molecular phylogenetic analysis was conducted based on the sequences of 18S rRNA genes. The carotenoid pigments were then extracted from the microalgae using water: methanol: dichloromethane (1:2:1,v/v/v). Further carotenoid pigments were then characterized using ultraviolet–visible (UV–Vis) spectrophotometry, FTIR, and HPLC. The antioxidant activity of the microalgae carotenoid extracts was determined with the 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging assay. The results showed that the microalgae belong to the species Mychonastes racemosus AUP1. Carotenoid extracts was obtained from microalgae were about to 86 mg/g dry weight extract was obtained from extraction process of microalgae. Based on FTIR, and HPLC analysis, the microalgae carotenoid extracts contained β-carotene (C40H56) and lutein (C40H56O4). The IC50 value of microalgae carotenoid extract was 78.61 µg/mL. This study suggests that microalgae Mychonastes racemosus AUP1 are potential sources for obtaining carotenoid with strong antioxidant activity. In the future, the microalgae Mychonastes racemosus AUP1 has the potential for prospection of functional foods.