Proximate and total fatty acid composition of some aquatic macrophytes in the Nile River Rayahs, Egypt

Abstract

Background and Objective: Myriophyllum spicatum, Ceratophyllum demersum and Eichhornia crassipes are economically important and widely distributed macrophytes species. The objective of the current study was to evaluate and compare the variations in proximate and fatty acid composition of these aquatic macrophytes with respect to macrophyte species and water characteristics of the sampling sites. Materials and Methods: Macrophytes were collected from five sites of River Nile Rayahs. A proximate analysis and high performance gas chromatography (HPGC) were used for evaluation of the nutritional components. Results: The results demonstrate a significance differences (p>0.05) between the three studied species regarding their nutritional components, in addition to their differential response to the different water variables. All the studied plants had a high organic matter content with the highest nitrogen free extract value (NFE) 77.55% in sample of E. crassipes from site 5. The highest protein, digestible crude protein, protein/lipid, protein/nitrogen free extracts, protein/energy contents, nitrogen and potassium contents were found in C. demersum from site 5. Moreover the highest metabolized energy, energy value of organic matter and Zn contents were recorded for M. spicatum from site 3. HPGC analysis of fatty acids indicate the presence of 10 saturated fatty acids (SFA), 6 monounsaturated (MUSFA) and 5 polyunsaturated (PUSFA), varied significantly in distribution with plant species and sampling site. Conclusion: This study reveals the economic potential of these macrophytes as a natural food resources for fish and animals especially C. demersum and M. spicatum from site 5.