Conducting Total Phenolic Content analysis
Author: Jeehye Seo | Major: Food Science | Semester: Spring 2025
Hi, my name is Jeehye Seo, and I am a Food Science major in Dale Bumpers College of Agricultural, Food and Life Sciences. Since last year, I’ve been conducting research under Dr. Sun-Ok Lee in the Food Science department. During the Spring 2025 semester, I focused on extracting Apio tuber and analyzing its total phenolic content (TPC) and antioxidant properties using DPPH and FRAP assays. After I graduate next semester, I plan to pursue a master’s degree.
My long-term goal is to become a leading expert in food science, using laboratory research to address global challenges and contribute to the Sustainable Development Goals such as no poverty, zero hunger, and good health and well-being. I am especially passionate about developing value-added products from surplus and underutilized agricultural resources, which can reduce waste, enhance food security and support sustainable development. Motivated by this vision, my current research explores the anti-inflammatory effects of bioactive compounds in Apio (Arracacia xanthorrhiza) tuber. Apio is a lesser-known tuber from the Andean region. By analyzing its antioxidant properties, I aim to evaluate Apio’s potential as a functional food ingredient that can combat free radicals and inflammation, which are linked to chronic diseases such as diabetes, cancer and cardiovascular disease. This research not only contributes to human health but also highlights the problems of underutilized crops in the global food system. Writing my proposal, I learned that there are many tuber vegetables or other crops underexplored, and our food system is limited to a few varieties due to industrial agricultural practices, and profit-driven selection only for the privileged instead of smaller, local farmers. Repositioning crops like Apio as valuable function ingredients can drive crop diversification, reduce over reliance on a few major staples and promote more nutritionally resilient food systems. Moreover, promoting sustainable crops like Apio can bring significant economic and social benefits to rural farmers, especially in the Andean region, by opening new market opportunities and income streams through the development of value-added products, similar to the successful commercialization of Moringa in African communities. I was excited to work with Dr. Lee because her research focuses such as bioavailability and bio efficacy of dietary phytochemicals and the development of innovative nutraceuticals aligned with my interests.
Performing the Total Phenolic Content (TPC) assay was my first research experience. Although a graduate student kindly provided me with a handwritten protocol, I initially struggled to understand it fully. I lacked confidence in almost every step, preparing serial dilutions, weighing samples accurately, selecting the right equipment, and even knowing where to dispose of chemicals with long, unfamiliar names. I was committed to doing everything properly, so I took great care not to make mistakes. Whenever I was unsure, I didn’t hesitate to ask questions or seek clarification. I also began recording videos whenever graduate students demonstrated procedures, which proved incredibly helpful for reviewing and reinforcing what I had learned. While it took time and was overwhelming at first, each challenge became a valuable learning experience that laid the foundation for my skills in lab techniques and data analysis.
The FRAP assay was also challenging because I had to rely solely on the manufacturer’s manual. Initially, I used sample concentrations that were too high, which gave out-of-range results. With advice from graduate students, I adjusted the dilutions and finally obtained consistent and accurate data in my third trial. In conclusion, the results from all analyses were consistent and suggest that both yellow and white Apio tubers have potential as functional food components, with white Apio showing greater potential. It was interesting to me, because I thought yellow samples would have higher potential of antioxidant properties based on the common understanding that color-pigmented foods such as purple rice or deep-colored vegetables tend to exhibit stronger antioxidant properties. Discovering that the less pigmented white Apio had greater potential taught me the importance of evidence-based research and made me more curious about the complex nature of bioactive compounds.
Later in the project, Dr. Lee and I planned to compare the antioxidant activity of apio tuber extracts obtained through traditional ethanol extraction with those produced using a supercritical CO₂ method in Dr. Ubetogullari’s lab. Unfortunately, we were unable to move forward with this comparison due to the large quantity of apio tuber required, which we did not have at the time. While it was disappointing, this limitation helped me understand the practical challenges researchers often face with materials and resources.
Dr. Lee played a central role in guiding my research, allowing me to participate in lab meetings, and helping me build foundational laboratory skills like pipetting, centrifugation, and dilution. I also received a lot of help from graduate students Inah Gu, Oluwatobi Amusat, and Annie Wang. They patiently answered my questions, walked me through assay procedures, and supported me whenever I felt stuck or unsure. Their mentorship was incredibly valuable, especially as this was my first research experience.
This summer I’m planning to present my findings at the US-Korea Conference (UKC) on Science, Technology, and Entrepreneurship. In Fall 2025, I will expand this research by conducting cell culture experiments. I’ll assess the anti-inflammatory effects of Apio extracts on LPS-stimulated RAW 264.7 macrophage cells, focusing on key mediators such as Nitric Oxide (NO), Interleukin-6 (IL-6), and Tumor Necrosis Factor-alpha (TNF-α). This will allow me more deeply explore the potential of Apio as a functional ingredient. I’m incredibly grateful for the support provided by the Honors College grant, which gave me the opportunity to gain valuable hands-on experience and grow as a researcher. I’ve learned a lot through this project, and I’m excited to continue it next semester.