Illinois Tech researchers uncover key insights on red raspberry polyphenols and their metabolites


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Chicago, IL — April 24, 2018 —

Britt Burton-Freeman, Ph.D., MS of the Center for Nutrition Research, Illinois Tech Institute for Food Safety and Health, recently published an exploratory study in Food & Function that offers new insights on red raspberry polyphenols and their metabolites after human consumption. The study uncovered the first report of breast milk as a pathway for red raspberry polyphenol metabolites.

The metabolic fate of red raspberry polyphenols, including their metabolites were characterized over 24 h. Among the 62 metabolites reported, some were detected for the first time, in plasma, urine, and breast milk.

Red raspberry intake has been associated with a decreased risk of developing several chronic diseases and many studies associate those health benefits with their polyphenol content. This study aimed to identify and quantify the polyphenols and their metabolites in human biological samples after acute and chronic intake of red raspberries to help design future studies on health benefits.

The findings suggest the most abundant polyphenols in red raspberries are anthocyanins and ellagitannins, which have gained attention due to their antioxidant and anti-inflammatory effects in lab bench and also human studies. This study identified polyphenols in four different forms of red raspberries (frozen, fresh, freeze-dried, pureed) and found that while the different forms have relatively similar polyphenol profiles, the concentration of anthocyanins was highest in the frozen red raspberry form and the concentration of ellagitannins was highest in the freeze-dried red raspberry powder form.

“To design studies investigating their biological effects, we needed to have a better understanding of the variability in key polyphenols among red raspberry fruit forms and their metabolic fate in humans after acute and chronic intake of red raspberries,” commented Burton-Freeman, the paper’s lead author.

“The knowledge of metabolites formed in human biological samples will aid research platforms in assessing health benefits and determining possible mechanisms of action with the goal of optimizing intake strategies to achieve their maximum benefits,” said Burton-Freeman.

The results of this study confirm and extend previous findings on red raspberry metabolites and offer new information for understanding the metabolism of these compounds and their composition in different biological specimens. This study assessed biological samples (urine, plasma, breast milk) obtained from two human pilot studies after consuming red raspberries for more than one week.

For the full study, click here.

About Illinois Institute of Technology

Illinois Institute of Technology, also known as Illinois Tech, is a private, technology-focused, research university, located in Chicago, offering undergraduate and graduate degrees in engineering, science, architecture, business, design, human sciences, applied technology, and law. One of 21 institutions that comprise the Association of Independent Technological Universities (AITU), Illinois Tech offers exceptional preparation for professions that require technological sophistication, an innovative mindset, and an entrepreneurial spirit.


Created in 2013, the National Processed Raspberry Council (NPRC) represents the processed raspberry industry and is supported by assessments from both domestic and imported sources. The NPRC is responsible for marketing processed raspberries in the U.S. and is committed to promoting the growth of the entire industry. Processed raspberries are frozen at the peak of ripeness to lock in flavor and nutrition. NPRC's mission is to invest in research on the health and wellness benefits of raspberry consumption and communicate the advantages of raspberries to consumers, food manufacturers and foodservice decision makers in order to build demand and secure the long-term viability of the industry. Learn more at


  • Zhang X, Sandu A, Edirisinghe I, Burton-Freeman B. An Exploratory Study of Red Raspberry (Rubus idaeus L.) (Poly)phenols/Metabolites in Human Biological Samples. Food & Function 2018.