ABSTRACT
Fish and shellfish are considered as a source of essential minerals and a well-balanced supply of minerals. Fish is a valuable source of calcium and phosphorus, and also iron, copper and selenium. Analyses of ash and mineral content of foods are for many reasons like nutritional labeling, fish quality, microbiological quality, fish nutrition, and fish processing. Wet ashing is employed when a specific mineral analysis of the sample is required. Ashing removes the organic matrix surrounding the minerals by digestion. Knowledge on the concentration and the type of specific minerals in aquatic food is of importance. Gravimetric analysis method precipitate the element from solution by the addition of a reagent first that reacts with it to form an insoluble complex. Spectrophotometric methods depend on the change in color of any reagent when it reacts with a specific mineral in solution. Quantify the color change by measuring the absorbance of the solution at a specific wavelength using a spectrophotometer.
