Green Approach to Valorize Abundant Aquatic Weeds for Nutrient-Rich Edible Paper Sheets Production in Bangladesh

Three edible aquatic weeds, helencha (Enhydra fluctuans), malancha (Alternanthera philoxeroides), and kalmi (Ipomoea aquatica), were used to produce edible paper sheets. The composition of the raw and paper sheet samples was analyzed, including proximate composition, amino acid content, minerals and heavy metal contents, and bioactive compounds. The dried raw and paper sheets showed similar proximate composition, with carbohydrates being the highest (50.38-64.63%), followed by crude protein (15.25-19.13%), ash (9.30-15.88%), and lipid (1.549-3.43%). The weeds and paper sheets were rich in essential minerals like Na, Ca, Zn, and Fe. Acceptable levels of heavy metals, including Ni, Pb, and Cu, were found. The paper sheets contained seven essential and eight non-essential amino acids. A. philoxeroides sheets showed the highest amino acid content (16146.81mg/100g), while I. aquatica showed the lowest (13118.67 mg/100g). The aquatic weeds paper sheets were rich in containing bioactive compounds and the number in E. fluctuans, A. philoxeroides, and I. aquatica paper sheets were 31, 33, and 40, respectively. There were no significant changes in the nutritional content of aquatic weeds in paper sheet form compared to the raw weeds which suggests promising prospects for the production and consumption as a source of nutrition and bioactive compounds.