Analysis of 20 trace and minor elements in soy and dairy yogurts by ICP-MS

• Published in: Microchemical journal Vol. 102; pp. 23 - 27
• Main Authors: Llorent-Martínez, E.J., de Córdova, M.L. Fernández, Ruiz-Medina, A., Ortega-Barrales, P.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-05-2012
• Subjects: ICP-MS; Microwave digestion; Nutritional value; Soy; Trace elements; Yogurt; Microwave digestion; Yogurt; Trace elements; ICP-MS; Nutritional value; Soy
• ISSN: 0026-265X; 1095-9149
• DOI: 10.1016/j.microc.2011.11.004

The content of 20 trace and minor elements in soy and dairy yogurts consumed in Spain has been determined using inductively coupled plasma-mass spectrometry (ICP-MS) after microwave digestion. This work presents two goals: a) to determine the nutritional value in terms of minor elements content, using recommended daily allowance data; b) to determine the levels of trace toxic elements and compare them with the acceptable daily intake values. The developed analytical method was validated by using both milk certified reference materials and recovery experiments over different yogurt samples, obtaining satisfactory results in all cases. In addition, a comparison between the levels of minor elements found in soy and dairy yogurts was performed. Much higher concentrations of Cu and Mn were found in soybean products (up to 30-fold higher) and minor differences were observed in the content of Fe and Zn. Other minor element found at higher concentrations in soy yogurts was Ni (effect usually observed in plant-origin foods), which was determined at levels up to 450ngg−1 in some samples. Finally, the levels of toxic elements were very low, even below the detection limit in some cases.
► A critical comparison of trace elements and minor nutrients content in soy and dairy yogurts is carried out. ► Levels of nutrients in soybean yogurts show their importance for individuals with intolerance to lactose. ► Due to the higher content of Ni in soy yogurts, they are not recommended for patients with severe allergies to this metal. ► The levels of potentially toxic elements are always below the toxicity threshold.