Effects of bottom sediment on the accumulation of nutrients in the edible green seaweed Caulerpa lentillifera (sea grapes)

Abstract

This study evaluated the effect of bottom sediment on the accumulation of nutritional composition in Caulerpa lentillifera (sea grapes) in Beibu Gulf, Guangxi, China. The proteins, amino acids, lipids, fatty acids, carbohydrates, and minerals as well as the monosaccharide composition of the polysaccharides in sea grape samples grown with and without bottom sediment (S1 and S2, respectively) were analyzed and compared. Calculated by dry weight, the results showed that the ash contents in S1 and S2 were 55.20% and 41.21%, the protein contents were 14.08% and 13.91%, the lipid contents were 0.78% and 0.82%, the total carbohydrate contents were 21.32% and 34.99%, and the water-soluble polysaccharide contents were 2.45% and 3.38%, respectively. The presence of bottom sediment increased the content of ash, mineral elements, and heavy metals in sea grapes; decreased the content of carbohydrates and polyunsaturated fatty acids; and had no significant effect on the content of proteins, lipids, saturated fatty acids, and monounsaturated fatty acids. Bottom sediment also had no effect on the monosaccharide composition of the sea grape polysaccharides. These results provide an additional research concept for selectively promoting the accumulation of functional nutrients of sea grapes by regulating the bottom sediment composition and offer a scientific basis for the further development and utilization of sea grapes as a functional food resource.