Trace and Macro Elements Concentrations in Selected Fresh Fruits, Vegetables, Herbs, and Processed Foods in North Carolina, USA

Trace elements are minerals that are required in small amounts to maintain normal physiological processes and function. Although required in very small amounts, trace elements such as iron, iodine, fluoride, copper, zinc, chromium, selenium, manganese and molybdenum are vital for maintaining health.

Fresh fruits, vegetables, herbs, and processed foods continue to be the major sources of essential trace elements in humans’ diet required for proper body development. However, food products can potentially be contaminated by toxic heavy metals (HMs) from environmental contamination or industrial food processing. Accordingly, this study investigated a comparative analysis of essential elements and potential toxic HMs concentration in food products in the Greensboro metropolis, North Carolina, USA.

A total of 49 food samples comprising of 16 difference fresh fruits, 17 fresh vegetables, 4 herbs, and 12 processed foods were purchased from local grocery stores and analyzed for iron (Fe), calcium (Ca), magnesium (Mg), nickel (Ni), zinc (Zn), copper (Cu), lead (Pb), cadmium (Cd), and chromium (Cr) by the use of flame atomic absorption spectrometry (FAAS). The concentrations of elements were subjected to a regression analysis to further gain insight of the inter-element association in the food samples.

The results showed that the concentrations of trace elements obtained in this study were generally within the normal trace element concentrations for food samples. Potentially toxic heavy metals such as Cd, Ni, and Cr were not detected in any of the food samples. The concentrations of Pb detected in some food samples are within the acceptable range of Pb concentrations for food samples. Strong correlations between Cu and Fe and between Ca and Fe were obtained in the food samples. The trace element concentrations in this study are also comparable to the concentrations of elements in food samples from other countries. Overall, the analyzed food samples contained adequate essential trace elements concentrations required in humans diet. There is no evidence of heavy metal food contamination that can endanger the public safety or pose health risk to food consumers in the Greensboro metropolis. However, the small Pb concentrations detected in the food samples necessitate a continuous monitoring of the levels of Pb in food samples to ensure public safety.

In general, the participants generally consumed more potatoes and processed foods than any other investigated fruits and vegetables. Future study includes analysis of food samples for other potentially dangerous elements such as mercury and arsenic.

Article by Tsdale F. Mehari, et al, from North Carolina A&T State University, Greensboro, NC, USA.

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