Water hyacinth was introduced as an ornamental crop species in many countries more than a century ago, because of their attractive blue, lilac to purplish flowers and round to oval leaves. They were supplied to many gardeners and horticulture institutes and were supposed to be a prized species. Soon, it was realized to be an invasive species due to their adaptability to a wide type of fresh water ecosystems and interference with human activities. Thus a huge amount of money, and efforts have been invested since then for their management. However, it was recently realized that they could be substainably managed in their natural ecosystem and used in biofuel production, generating ample avenues of research, development and marketing of their end product (i.e. bioethanol and biogas). As the search for alternatives to fossil fuel intensifies in this age of modernization and industrialization, fuelled by increasing energy costs, water hyacinth holds a strong promise in the 21st century biofuel industry. The antoxidative properties of water hyacinth leaves were investigated by evaluating the scavenging capacity of liquid extracts in a competitive protective process against oxygenated free radicals (OFRs) released via electrolysis in a phosphate buffer with a Pt electrode. Colorimetric measurements carried out at 515 nm, through a N,N-diethyl-1,4-phenylenediamine (DPD) assay, showed a decreased absorbance of the sample, as compared to the blank obtained by electrolysis of the buffer without plant extract, revealing, thereby, the presence of antioxidizing agents in the liquid extracts. The antioxidative activity was estimated in terms of equivalent-glutathione (EG, in nmoles equivalent-glutathione per gram of dry plant material selected (eg/gdp)), and compared to those of soya beans and garlic bulbs. The EG value increased with decreasing dilution factors, regardless to the plant type, suggesting a strong influence of the medium pH on the antioxidizing agent extraction yields. Various plant drying procedures, namely: sunlight exposure (at 25–30 °C), heating (40 and 60 °C) and freeze-drying (at –70 °C) were also examined. The highest EG (ca. 40 nmol eg/gdp) was observed for freeze-dried leave extract, while the lowest value was obtained upon heating at 60 °C (16–17 nmol eg/gdp), presumably due to a detrimental effect of increased temperature. The glutathione content in the plant extracts was further determined spectroscopically at 412 nm, through an enzymatic assay, using glutathione reductase. Small but interesting contents of glutathione (ca. 40 nmol eg/gdp) were found in the hyacinth leaves, making this plant to be regarded as an alternative and convenient low-cost raw material for antioxidizing agent recovery.
Water Hyacinth (Eichhornia crassipes Martius) is a monocotyledonous freshwater aquatic plant, belonging to the family Pontederiaceae, related to the lily family (Liliaceae) and is a native of Brazil and Equador region. It is also a well known ornamental plants found in water gardens and aquariums, bears beautiful blue to lilac colored flowers along with their round to oblong curved leaves and waxy coated petioles. It grows from a few inches to about a meter in height. The stem and leaves contain air filled sacs, which help them to stay afloat in water. Other useful sources of floriculture related data for ornamentals include national governments, the International Association of Horticultural Producers, the United Nation Comtrade statistics publications and various online trade journals. The value of additional aspects of floriculture related products are even more difficult to determine (Chandler and Lu 2005; Chandler and Tanaka 2007). Precise data on the various aspects of the water hyacinth as an ornamental crop is not available for different countries of the world, as considerable amount of unrecorded economic activities take place in local markets.In the developing...