Optimization of extraction parameters for bioactive compounds from Sargassum cinereum using ultrasound-assisted extraction with insights into their chemical and nutritional composition

Abstract

Marine organisms, particularly macroalgae, are globally recognized as key sources of valuable biomolecules with applications in the agricultural and pharmaceutical sectors. They are also an inexpensive source in developing countries with high population density, such as India, where pressing demands conflict with the sustainable use of resources. The abundance of Sargassum spp. in India could provide an opportunity to create cost-effective marine-derived natural products, and the implementation of an optimized extraction and scaling process could contribute to overcoming sustainability issues. Thus, the present study examines the nutritional, mineral, and fatty acid composition of Sargassum cinereum J. Agardh from the Karnataka coast. Ultrasound-assisted extraction (UAE) was used to optimize the yield of bioactive compounds using the Response Surface Methodology (RSM) with the Box–Behnken design (BBD). Carbohydrates were the most abundant (53.15%) macronutrients, followed by fiber (20%) and protein (13.35%) on a dry-weight basis. Fatty acid composition showed abundance of palmitic acid, with a varied mineral composition, similar to other macroalgae already in use as a feed ingredient. RSM-BBD analysis underscored the impacts of solvent concentration, extraction time, and the solid-to-solvent ratio on the yields of total phenolic content, total flavonoid content, and antioxidant activity. The optimized parameters provide clear evidence of the interaction effect, presented through second-order polynomial equations. Although differences may arise depending on sample processing techniques, geographical variability, storage conditions, and the possible degradation of sensitive compounds, the data obtained herein highlight the need for future studies, given the potential of Sargassum spp., which grows abundantly, is nutritionally and chemically rich, and can be a high-value compound and used for multiple purposes.