Chemical, Microbial Quality, and Risk Assessment due to Toxic Metal Contamination of Egusi (Citrullus colocynthis L.) Powder Sold in Selected Ghanaian Markets

The present study was undertaken to investigate the physicochemical and microbiological qualities of melon seed powder sold in some open Ghanaian markets. Twenty-five samples of powder were collected randomly from each of four major markets and analyzed for moisture, pH, total ash, acid insoluble ash, and free fatty acids (FFA) using standard methods. The microbial population was determined using the pour plate method. Melon seed powder samples had a neutral pH (6.9-7.3) and contained significant amounts of ash (0.1-0.6%). Acid insoluble ash of powder from one market was high (0.6%) and possibly indicate contamination with siliceous earth material. FFA ranged between 4.1 and 11.6% for powder from the four markets. Levels of lead were higher (0.4-0.8 ppm) than other metals such as cadmium (0.02 ppm) and copper (0.3-0.6 ppm). HQ values >1 were recorded for Pb, implying a greater risk of toxicity to consumers. Counts for aerobic bacteria, fecal coliforms, and yeast and molds were in the range of 3.2-4.4, 1.6-4.0, 1.4-2.8, and 1.1-3.2 log CFU/g correspondingly for these organisms. E. coli was not detected in any of the melon seed powder samples analyzed. This study highlights the need for proper handling of melon seed during processing, storage, and distribution, to safeguard its quality for consumers.

Making a synthetic zeolite from a residue of bauxite washing

A zeolite synthetic of NaA type is generally prepared by mixing the alumina and silicate-containing materials (alkali alumino hydro-silicates). The used raw materials include the amorphous solids such as metakaolin, siliceous earth, coal ash, kimberlite waste, alumina trihydrate [Al(OH)3], bauxite, and aluminum metal. Residue of bauxite washing retains a fine texture and contains significant alumina and silica content, namely 30-36% Al2O3 and 10-15% SiO2. Both components are required for making the zeolite NaA . In this research, the zeolite NaA was made by extracting the alumina from residue of bauxite washing with caustic soda, and followed by reacting it with a water glass after through the flushing and washing process. The composition of zeolite NaA is as follows: 33.87% SiO2, 27.63% Al2O3, 16.31% Na2O, and 22.18% H2O with Na96Al96Si96O384.216H2O or Na12(AlO2)12(SiO2)12.27H2O as its mineral composition.