Mineral Constituents Profiling of Ready-To-Drink Nutritional Supplements by Inductively Coupled Plasma Optical Emission Spectrometry

Abstract

Nutritional drinks (NDs) are medicinal food products intended for people with different health issues constricting nutrients provision. Eight varieties of milkshake style NDs were analyzed in this work. Prior to element analysis, they were freeze-dried, and concentrations of twenty macro- and microelements in analyzed samples were simultaneously measured by ICP-OES after their mineralization in a closed-vessel microwave-assisted digestion system. Results of this analysis indicated that these NDs must be considered as nutrient-dense foods, taking into account mineral constituents. Consumption of two bottles of such NDs per day provides very a high amount or even an excess of human daily requirements set as Recommended Dietary Allowances (RDAs). Generally, concentrations of determined elements in examined NDs were consistent with data given on the labels—most of differences did not exceed 30% (median: −5.91%, standard deviation: 14%). Discovered very strong and moderate positive correlations between concentrations of major and essential elements (Ca, Mg, P, Cu, Fe, Mn, Zn) were likely due to their incorporation into formulations of analyzed NDs. However, relationships between contents of trace elements were the result of concomitance of these elements in substrates used for examined products production or contamination of substrates.