Leinen’s research published in international journal

February 11, 2019

Lucas Leinen knows more about preserves than he ever thought he would.

The Dakota State University senior from Aberdeen, S.D. experimented with 1950s homemade goods canned last summer, part of his work as a summer research fellow at the Madison, S.D. university. He analyzed several samples a day using a gas chromatograph-mass spectrometer, or GC-MS. This piece of scientific equipment separates and analyzes volatiles, which are the gaseous compounds released when canned goods are opened.

What Leinen learned by studying these volatiles will be published this month in a special edition of the international scientific chemistry journal “Molecules.”

“Lucas’s paper is an invited paper, which is an extremely rare achievement for an undergraduate,” explained Dr. Michael Gaylor, associate research professor and Leinen’s research mentor. It is also an excellent accomplishment to list on Leinen’s graduate school applications. He has applied to several schools around the world, from USD and SDSU to the Universities of Bristol and Melbourne in Australia, and the University of Hawaii. After earning his Ph.D. he hopes to do industry research in chemistry.

Leinen’s summer’s research project, sponsored by the NASA South Dakota Space Grant Consortium and the DSU Provost’s Office, was part of a lengthy scientific process that began in 2016, when the department was given a jar of preserved pumpkin prepared in 1920. The 100-year-old contents of that jar could offer some interesting insights into the chemical environment in which the food was prepared, but before the student researchers open the rare jar, they needed to “develop a repeatable method,” of the experimental process, said Leinen.

His summer research involved testing more than 100 new jars of store-bought pickles and maraschino cherries, before moving on to the 1950s canned foods that had been donated to the chemistry department. This gave him the opportunity to compare the sweet and savory chemical properties of the aroma compounds released from industrial canned foods versus those released from homemade canned foods.

The process yielded some unexpected discoveries. Several of the 1950s preserves showed substantial amounts of the chemical Bisphenol-A (BPA), which could be from plastics lining the jar lids, Leinen said. These may “be some of the first BPA-containing products in the U.S.,” he wrote in the article’s abstract.

Leinen also saw how versatile scientific testing can be. He has used similar techniques to analyze volatiles released from land-applied sewage sludge. “It was interesting how wildly different the solid-phase microextraction (SPMD) method developed for this study can be.”

It was also surprising how some of the older food preserves were still edible. “The apples tasted like apples, the onions like onions, the pickles tasted like today’s pickles,” he said. But after smelling the “putrid” volatiles released by the almost 70-year-old jar of mincemeat, he didn’t give that a try.

The article will appear in the February special edition of the journal “Molecules.”