Instant food products as a source of silicon

Silicon is a trace element for humans, and is absorbed from food in the form of orthosilicic acid. Instant food products are part of a constantly growing market of convenience foods, which have not been evaluated yet as sources of silicon. In this study the total and soluble silicon contents in different instant food products were determined by using graphite furnace atomic absorption spectrometry (GF-AAS). A selection of instant products commercially available in Wroclaw were analyzed: soups, main courses, coffee drinks, jellies and puddings. Total silicon contents in soups, main courses and coffee drinks ranged widely and reached the values: 0.10–30.20, 0.63–37.91 and 0.21–13.37 mg/serving, respectively. These products contained 0.05–1.26 mg of soluble silicon per serving. The total silicon content in jellies and puddings did not exceed 0.36 mg and 2.42 mg/serving, respectively. Among the analyzed desserts the highest level of soluble silicon was found in chocolate puddings: 0.36–0.41 mg/serving. The silicon level in servings of the studied instant products when prepared with the appropriate amount of water was also estimated. The mean content of silicon determined in samples of drinking water from Wrocław and the vicinity, which was used for the estimation, amounted to 7.09 mg/l. The total silicon content in ready-to-eat products ranged from 1.32 to 39.21 mg/serving. In conclusion, some of the analyzed instant foods contained very high amounts of silicon, however the content of the soluble, and hence available, form of this element was low.