Queen's University

A risk assessment of toxic elements in gluten-free and rye breads and the effect of toasting bread on the bio-accessibility of those elements using ICP-MS

This project was supervised by Dr. Diane Beauchemin from the Department of Chemistry at Queen's University.

Bread is a common staple in the North American diet with over 4 million tonnes consumed in the US annually. The popularity of breads made from alternative grains (such as rye, quinoa, pumpernickel, and spelt) and the increase in gluten free (GF) alternatives (made from a mixture of rice and other alternative grains) has significantly contributed to this growth. While the hunger for alternative breads is increasing, there is very little research into the risks associated with consuming breads made from alternative grains. Studies have shown that many grains can contain high levels of toxic elements, especially if they are grown in soils with high levels of these elements. A previous study investigated the risk associated with toxic elements in rice, and concluded that these elements are highly bio-accessible when the rice is not washed before processing. It is therefore extremely important to investigate the risk and bio-accessibility of toxic elements in these popular alternative breads. My project aims to quantitatively determine the toxic element composition of rye and gluten-free breads using Inductively Coupled Mass Spectrometry (ICP-MS). The effect of toasting the breads on the bio-accessibility is also being studied, as some toxic elements can be converted from their toxic forms to volatile or non-toxic forms after heating. Finally, speciation analysis will be done to determine if the most abundant elements are in their toxic or non-toxic forms.