A comprehensive analysis of alginate content and biochemical composition of leftover pulp from brown seaweed Sargassum wightii

Utilization of total biomass of any feedstock for integrated production of food, energy and other valuable products with zero waste is a relatively new and novel idea where abundant literature is not available. Similarly, fragmented data are available on analysis of leftover pulp after extraction of important polysaccharides from seaweeds. Seaweed industrial wastes i.e. the remaining pulp after extraction of high value polysaccharides such as agar, alginates, carrageenan still contain high amount of carbohydrates and other nutrients which may be used as a source of raw material for various industries. In this study, Sargassum wightii, common to the Indian coastline, has been investigated for seasonal variations in the alginate content as well as biochemical composition of its leftover pulp over a period of two years. Present investigation reveals that alginate and left over pulp content fluctuate as a function of seasonality and as well as different vegetative parts of the thallus. Maximum alginate content were recorded during March from main axis (~ 33%) whereas amount of leftover pulp were maximum during July from young blades (~ 47%). Interestingly, the leftover pulp contained high amount of insoluble carbohydrates (~ 47%) and ash content (~ 30%). Significant correlations between environmental factors and alginate content as well as chemical composition of its left over pulp were also observed.