Locally grown fruit retains its soil signature: using the scanning electron microscope to bridge soil science to fruit spreads

Wednesday 11:15-11:45am PT / 12:15-12:45pm MT / 1:15-1:45pm CT / 2:15-2:45pm ET Online


Nina Baghai Riding, Delta State University
Larry Collins, Delta State University
Chuck Smithhart, Delta State University
The need to transform the undergraduate laboratory experience in order to provide students access to authentic research opportunities has been well documented. At Delta State University, students enrolled in Materials and Methods of Environmental Science investigated whether fruit associated with different areas of the United States could correlate to soils in which they were grown. During the past five spring semesters (2017-2021), 25 noncommercial fruit spreads were studied: cactus marmalade from Tucson, Arizona, grape jelly from Mills, Massachusetts, blackberry jam and muscadine jelly from Cleveland, Mississippi, strawberry preserves from Fredericksburg, Texas, peach jam from Laurel, Virginia and Nampa, Idaho, blue elderberry jam and plum jam from Lincoln Co., Nevada and more. Each sample was cooked on a hot plate for a week and then divided into crucibles and placed in a Muffle Furnace for 24 hours at 1,000 °C to generate an ash. The ash samples were analyzed with an energy dispersive x-ray unit associated with a JEOL scanning electron microscope to determine elemental composition. The National Conservation Resource Service soil website was used to establish the local soil types that were associated with each sample. Altogether, 21 chemical elements were noted and many of the samples were associated with the local soils. For example, a calcium spike occurred in samples from Lincoln County, Nevada, which is probably due to limestone rich soils and samples from the Mississippi Delta yielded the most elements possibly due to periodic flooding by the Mississippi River and its tributaries that covered the area prior to levee construction. Overall, this study links geology, chemistry, soil science, and scientific methodology and the results are of broad relevance to the scientific community. Success of this project is further documented by peer-reviewed posters, an international paper, and presentations that have been given at professional conferences.

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