The seasonal variation in the nutrient composition of Enhydra fluctuans and Marsilea quadrifolia, two edible semi-aquatic plants, was studied in order to promote their consumption as green leafy vegetables. Both plants had a high crude protein content throughout all harvesting seasons. Enhydra fluctuans had a low ash content and was a good source of beta-carotene (3.7 to 4.2 mg/100 g on a fresh weight basis). Marsilea quadrifolia exhibited wide fluctuations between seasons and was not very promising in nutrient composition when compared to other commonly used green leafy vegetables.

In a study conducted on the extraction of protein from the leaves of 30 freshwater aquatic plants, the highest standing crop fresh yield was found in Typha latifolia (2650 g/m2). The Bio-Medical Data Processing (BMDP) K-means clustering program with K = 2 showed that 11 of the 30 plants had a high protein nitrogen extractability as well as a high nitrogen content of the extracted protein. Among these, leaf protein from Allmania nodiflora had the highest content of crude protein (62.7%) and beta-carotene (782.4 micrograms/g). Leaf protein prepared from Hygrophila spinosa, Ottelia alismoides and Polygonum barbatum had low in-vitro digestibility. The levels of alkaloids and polyphenols were lower in the extracted protein compared to that present in the original leaf sample.

Proteins extracted from the leaves of Alternanthera philoxeroides, Lemna minor, and Pistia stratiotes were evaluated for their nutritional quality using rat feeding experiments. It was found that a 3% level of supplementation of leaf protein extracted from L. minor and P. stratiotes significantly improved the nutritive value of a wheat flour diet, thereby indicating that they could be used as supplements in feeds or foods to improve the quality as well as protein levels of deficient diets. Keywords: Aquatic weeds; leaf protein; rat experiments

Fresh leaves of Ailanthus excelsa and three protein fractions, unfractionated, chloroplastic, and cytoplasmic, as well as pressed cake left after extraction of protein were subjected to proximate analysis. The cytoplasmic protein fraction contained 62.71 % crude protein, while whole leaf contained 20.86%. The unfractionated and chloroplastic protein fractions contained more crude fat than the whole leaf and pressed cake. Compared to whole leaf and pressed cake, protein fractions were low in crude fiber. The presence of polyphenols was also studied. The amino acid composition of the cytoplasmic fraction also showed an excellent balance of essential amino acids. Results indicated that the leaf protein fractions from A. excelsa were nutritionally superior to the whole leaf, pressed cake, and soyabean protein.

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