Fruits and vegetables, and their products like any other foods contain organic matter which must be destroyed prior to the estimation of minerals.
To determine the total mineral content in a food, the ashing procedure is usually the method of choice. Dry ashing or wet digestion is generally used for the destruction of organic matter. Wet digestion with acids is the most common technique used for decomposition of organic matter, especially food material. Wet ashing is normally for a high fat content such as meat products or for preparation for elemental analysis.
To completely destroy the organic matrices, the addition of stronger oxidizing agents, such as hydrogen peroxide is sometimes necessary.
The final determination of inorganic components in foods is done by spectrophotometric methods including absorption spectrometry (AAS) and atomic emission spectrometry (AES) using flame, inductively coupled plasma or an electro-thermal device for atomization.
Atomic emission spectrometry differs from atomic absorption spectroscopy in that the source of the radiation is in fact the expected atoms or ions in the sample rather than an external source has in part taken over.
Atomic emission spectrometry does have the advantages with regards to sensitivity, interference and multi-element analysis.
Mineral analysis of food
