Extraction of Edible Leaf Protein Concentrate from Water Hyacinth Oyeyemi Adeyemi Federal University of Petroleum Resources, PMB 1221, Effurun. Delta State, Nigeria.

ABSTRACT Water hyacinth (Eichhonia crassipes) is one of the aquatic weeds. It infests rivers, dams, lakes and irrigation channels on every continent except Antarctica. The coverage of water ways by water hyacinth devastates aquatic environment and costs billions of dollars every year as control costs and economic losses.

ABSTRACT In these days of diminishing natural resources, it has become necessary to investigate the existing resources in water hyacinth for production of food, food additives, pharmaceuticals and raw materials for agro-allied industries. The aim of this study was to convert water hyacinth from an environmental nuisance to a natural resource that is in high demand. Edible form of water hyacinth leaf protein concentrate (WHLPC) was extracted.

ABSTRACT The physicochemical characteristics, total alkaloids and phenolic compounds of the WHLPC were determined. Proximate composition and amino acid profile of the WHLPC were analyzed and the LD50 evaluated. The WHLPC was used to formulate feed using different concentrations (7.73, 15.46, 23.19, and 30.92) %w/w. A control feed was formulated with soybean (15.46%w/w) in place of WHLPC.

ABSTRACT The resulting feeds were fed to different groups of rats over a period of twenty (20) weeks and the growth was monitored. Growth response curve of rats placed on formulated feed showed positive slope. At the end of the experiment, rats in various groups gained weight, gain in body weight measured in Control rats (55.35 g), WHLPC1 rats (57.75 g) were not significantly different (p>0.05). Data revealed that WHLPC is a potential raw material for food and beverages industry.

Study Area . The study area (River Ijana) is located within longitude 5.540E and 5.70W and latitude 5.310N and 5.60S as shown in Figure 1.

Figure 1: Map of Warri Showing the Sample Collection Area (River Ijana)

Extraction of WHLPC The method described by Wenbiao and Yanling (2010) was modified and used. The water hyacinth leaves collected from Ijana River were thoroughly washed in water, and blanched for 5mins with 5% acetic acid, in a heating mantle. The leaves were then rinsed in de-ionized water and allowed to dry at room temperature.

Extraction of WHLPC Furthermore, the leaves were soaked in 95% ethanol for 6hrs to remove the fat and then dried in an incubator at 45°C to obtain the water hyacinth leaf protein concentrate (WHLPC). The now formed water hyacinth leaf protein concentrate (WHLPC) was ground in a Teflon base grinder and stored in an air tight container, for further analysis.

Other methods Heavy metal analysis of WHLPC was done with an Atomic Absorption Spectrophotometer (AAS), using the American Public Health association (APHA, 1995) guidelines. Concentration total alkaloids of WHLPC was determined by the method described by Harbone (1973). The proximate analysis of water hyacinth leaves was carried out according to the method described by AOAC (2005).

WHLPC – Water hyacinth leaf protein concentrate *Soy protein Table 1: Ingredient composition (%) of the experimental diets Group Corn starch Protein sources Soy oil Fish meal Vitamins + Minerals Control 60 15.46* 8 15.22 1.32 WHLPC1 7.73 22.71 WHLPC2 15.46 23.19 7.49 WHLPC3 30.92 0.00 WHLPC – Water hyacinth leaf protein concentrate *Soy protein

Concentration (mg/kg) *Upper limit (mg/kg) Table 2: Heavy metal composition of Water hyacinth leaf protein concentrate Metal Concentration (mg/kg) *Upper limit (mg/kg) Cd 0.02±0.001 0.05 Cr 0.13±0.001 1.0 Pb 0.001±0.00 0.1 Pt Pd 0.003±0.001 Sn Hg

Fe 0.001±0.00 5.0 Mn 0.05 Cu 0.5 Zn 24.0 Ni Co 1.0 *Source: WHO (1989)

Each value represents mean ± SEM of five determinations. Table 3: Proximate composition of Water hyacinth leaf protein concentrate Nutrient Concentration (%) Protein 56.38±2.15 Fat 4.11±0.55 Ash 4.88±0.24 Fibre 1.02±0.05 Carbohydrate 33.61±1.55 Each value represents mean ± SEM of five determinations.

Amino Acid Concentration (g/100g) FAO STANDARD (g/100g) Alanine Table 3.3: Amino Acid composition of Water hyacinth leaf protein concentrate Amino Acid Concentration (g/100g) FAO STANDARD (g/100g) Alanine 3.20±0.15 NA Arginine 3.80±0.23 Aspartic acid 4.96±0.25 Cysteine 0.72±0.01 Glutamic acid 6.04±0.52 Glycine 3.00±0.12 Histidine 1.10±0.09 Isoleucine 2.29±0.32 4.2

Leucine 5.01±0.35 4.8 Lysine 3.72±0.48 4.2 Methionine 1.34±0.08 2.2 Phenylalanine 3.67±0.22 2.8 Proline 2.72±0.11 NA Serine 2.52±0.15 Threonine 2.60±0.17 Tyrosine 2.20±0.13 Valine 2.81±0.11 Each value represents mean ± SEM of five determinations. NA: Not Available

Concentration (mg/kg) Total alkaloid 16.6±0.2 Phenolic compounds Table 4: Total Alkaloids and phenolic content of Water hyacinth leaf protein concentrate Phytochemical Concentration (mg/kg) Total alkaloid 16.6±0.2 Phenolic compounds 6.0±0.1 Each value represents mean ± SEM of five determinations.

Table 5: Results of LD50 test of Water hyacinth leaf protein concentrate Rat ID Dose (g/kg.bw) Short-term result (48 h) Long-term result (12 days) A 3.25 Survival survival B 8.37 C 17.51 D 21.50

Figure 2. presents the growth response of rats placed on feed formulated with water hyacinth leaf protein concentrate (WHLPC) over a period of twenty weeks.

CONCLUSION Experimental evidence from the present study revealed that; Water hyacinth is a good source of leaf protein concentrate The water hyacinth leaf protein concentrate (WHLPC) is nutritious as evidenced by proximate composition

CONCLUSION WHLPC contains alkaloids and phenolic compounds at physiologic amounts WHLPC is not acutely toxic as revealed by the studies on LD50 WHLPC supports normal growth in rats and compared favourably with soybean

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