Ron Wrolstad talks with
ScienceWatch.com and answers a few questions about
this month's Emerging Research Front in the field of
Agricultural Sciences. The author has also sent along
images of their work.
Article: Anthocyanins, phenolics, and antioxidant
capacity in diverse small fruits: Vaccinium, Rubus, and
Authors: Moyer, RA;Hummer, KE;Finn, CE;Frei,
Journal: J AGR FOOD CHEM, 50 (3): 519-525 JAN 30 2002
Addresses: Oregon State Univ, Dept Food Sci & Technol,
100 Wiegand Hall, Corvallis, OR 97331 USA.
Oregon State Univ, Dept Food Sci & Technol, Corvallis,
OR 97331 USA.
King Coll, Bristol, TN 37620 USA.
(addresses may have been truncated.)
Why do you think your paper is highly
There continues to be intense interest in the phytochemical composition and
antioxidant properties of fruits and vegetables because of their possible
health benefits. While there have been several surveys reporting the
antioxidant properties of a wide range of fruits and vegetables, this study
focused on a large sampling (107 genotypes) of Vaccinium,
Rubus, and Ribes. Some key findings were a high
correlation between phytochemical composition and antioxidant properties,
and a wide range of total anthocyanins, total phenolics, and antioxidant
properties within the three genera.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
Our laboratory has a number of other publications on the phytochemcal
composition and antioxidant properties of various fruits, published prior
to and after this paper. The analytical methodology and experimental
approach is not all that novel in this paper. I suspect that its high
citation is because of the sampling. The senior author, Richard Moyer,
carefully selected all samples from two sites in the Willamette Valley. He
also conducted all analyses, except for the oxygen radical absorbance
capacity (ORAC) and ferric reducing ability of plasma (FRAP) measurements,
which were done at the Linus Pauling Institute at Oregon State University.
The wide range in total anthocyanins, total phenolics, and antioxidant
properties within the three genera has strong implications for
plant breeders and horticulturists. An interesting finding is that for
highbush blueberries, small berry size was highly correlated with
phytochemical content and antioxidant properties because of the higher
proportion of skin where these compounds are concentrated.
Would you summarize the significance of your paper in
This paper reports the anthocyanin pigment content, total phenolics, and
antioxidant properties for a large sampling (n=107) of blueberries,
blackberries, red and black raspberries, and red and black currants. The
phytochemical content is highly correlated with the antioxidant values.
Many believe that these properties are related to the positive nutritional
benefits of fruits.
The study showed a wide range of values within the different fruit
varieties, suggesting that plant breeders have the potential for developing
so-called "super-fruits" with high phytochemical content and antioxidant
values. An interesting finding that was particularly true for blueberries
was that small berry size was highly correlated with phytochemical content
and antioxidant properties because of the higher proportion of skin where
these compounds are concentrated. For highbush blueberries (V.
corymbosum L., fruit size was inversely correlated (r = 0.84) total
How did you become involved in this research and were
any particular problems encountered along the way?
the absorption and metabolism of
these compounds and their mechanism
of action is a very active research
Our laboratory has worked on the phytochemical composition of fruits and
vegetables and its impact on quality for many years. Some major issues have
been the color quality of fresh and processed products, and fruit juice
authenticity. We have enjoyed a long-term positive collaborative working
relationship with OSU Horticulture faculty and USDA scientists. Anthocyanin
pigments and polyphenolics are of particular interest, and research on
their possible health benefits was initiated through cooperative projects
with scientists at OSU's Linus Pauling Institute.
It was our good fortune when Richard Moyer, biochemist and Associate
Professor in the Biology Department at Kings College in Bristol, TN,
received sabbatical support from Kings College to work with USDA plant
breeder Chad Finn, Kim Hummer of the USDA-ARS Germplasm Repository, and
myself on the phytochemical composition and possible health benefits of
small fruits. Richard has a keen interest in the health benefits of fruits
and wanted to gain expertise in the analysis of anthocyanins and
polyphenolics, and also take advantage of the plant materials available at
OSU. This quality of this publication is largely due to the skill and
effort of Richard Moyer.
Where do you see your research leading in the
As corresponding author, I retired in 2004 after 40 years service at OSU,
and no longer have an active laboratory research program. However,
colleagues Chad Finn, Kim Hummer, and Balz Frei are actively engaged in
research at OSU, and Richard Moyer is active in teaching, outreach, and
research at Kings College.
Do you foresee any social or political implications for
With the assumption that human health is a social issue, then research on
anthocyanin pigments and polyphenolics and their possible health benefits
is important. Research on the absorption and metabolism of these compounds
and their mechanism of action is a very active research area. Basic
information on food composition and how it is affected by processing
continues to be needed. We need to have an understanding as to why
increased consumption of fruits and vegetables is related to a healthier
Ronald E. Wrolstad
Distinguished Emeritus Professor
Department of Food Science & Technology
Oregon State University
Corvallis, OR, USA