Optimization of Sargassum cinereum bioactives extraction parameters using ultrasound-assisted extraction with insights into 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 addressed the nutritional, mineral, and fatty acid composition of Sargassum cinereum J. Agardh from the Karnataka coast. Ultrasound-assisted extraction (UAE) was also used for optimizing bioactives yield using RSM-BBD. Carbohydrates were the most abundant (53.15 %) macronutrients, followed by fiber (20 %) and protein (13.35 %) on dry weight basis. Fatty acid composition showed the abundance of palmitic acid, with a varied mineral composition, similar to other macroalgae already in use as a feed ingredient. RSM-BBD analysis underlined the impact of solvent concentration, time, including solid-to-solvent ratio, on the yield of total phenolics and flavonoids content, and antioxidant activity. Optimized parameters clearly evidence the interaction effect, presented through second-order polynomial equations. Although differences may be stated depending on sample processing techniques, geographical variability, storage conditions, and possible degradation of sensitive compounds, the data obtained here raise interest in future studies, given the potential of Sargassum spp., which grows abundantly and is nutritionally and chemically rich, and can be highly valued and used for multiple purposes.