FST Ph.D. student Katherine (Katie) Uhl and her research advisor, Professor Alyson Mitchell, have published the first paper characterizing the aroma profile of blue elderflowers. Their paper, “Headspace Volatile Organic and Phenolic Compounds in Elderflowers and Elderflower Teas of Blue Elderberry (Sambucus nigra ssp. cerulea)” was selected as the cover image for October 2022 (above) for the journal ACS Food Science & Technology.
As Dr. Mitchell relates, “The demand for elderberry products has exploded in recent years, and most commercial products are made from European subspecies. Blue elderberry (Sambucus nigra spp. cerulea) is subspecies native to California and other western states. This fire-resilient and drought-tolerant plant is grown primarily in hedgerows for its ecological benefits (i.e. providing habitat and shelter for pollinators and improving soil quality). To date, the flowers and berries are rarely harvested although the blue elderberry can be considered a more sustainable option than European elderberries. To address this, we characterized the phenolic compounds and headspace volatile organic compounds in flowers and in teas made from these flowers for the first time. The predominant phenolic compounds identified were isorhamnetin-3-O-rutinoside and rutin. Levels of all phenolics increased with tea infusion time. One of the prevalent aroma compounds, that appears unique to this subspecies, is methyl eugenol. Our data demonstrates that native blue elderflower can be used in for food and beverage applications like other elderberry subspecies and that there are unique differences between the subspecies than can be exploited in product differentiation.”
"I am honored to have been selected to create the artwork for this issue of ACS Food Science & Technology. I wanted to let the elderflower's simple beauty shine through and really capture the reader's eye, so using this close up photo I took while harvesting the flowers was an easy choice. I hope readers will see these amazing flowers, blooming on a sunny morning near Davis, California, and go to the article to find out more about the flower of the blue elderberry. This is a wonderful culmination of several years of hard work by a lot of people who helped with this project and are also champions of the blue elderberry, and I hope they are excited to see it exhibited in this way for the world to see." - Katie Uhl
Katie’s research in Dr. Mitchell’s lab focuses on food chemistry and analysis, using techniques such as spectroscopy and chromatography. Her main project focuses on the characterization of bioactive components in California elderberries, including phenolics, volatile flavor compounds, sugars, and organic acids. This work helps to understand a currently under-utilized crop in California that has potential for value-added products. She has also worked in collaboration with the UC Davis Honey and Pollination Center to develop a method for characterizing mono-floral honey varieties by their volatile profiles. Katie now works as a Food Scientist at MeliBio, a startup in Oakland, CA making honey without bees to envision a more sustainable system for all pollinators.