Agriculture Reference
In-Depth Information
their potential antioxidant value. Wu et al. compared the antioxidant capacities of
many common foods. Putting the two efforts by Wu et al. together, we can establish
that the anthocyanins correlate with the increased antioxidant potential of foods.
Many of these foods could be considered as functional because of the high potential
to deliver antioxidant protection. As a population, we have to either convince the con-
sumer to consume more of the highly protective foods or deliver formulated foods
that deliver the benefits with low levels of consumption of fruits and vegetables.
Because the components must be absorbed to become effective, the relationship
between chemical analyses and the ultimate health benefit remains controversial.
Cao et al. (1998) demonstrated in a clinical trial that increased consumption of fruits
and vegetables resulted in a lower level of oxidative stress, while a high-fat diet
increased oxidative stress.
If it can be clearly demonstrated that the improved antioxidant status prevents
chronic diseases and that the antioxidants from foods are available, it raises new
opportunities to deliver convenient foods with high antioxidant capacity.
f
L a v of in of i D s
Flavonoids represent a large family (over 5000 identified) of bioactive compounds
derived from fruits and vegetables that deliver high antioxidant activity. Table 13.1
includes examples of flavonoids found in some common foods. These materials can
be concentrated and used as food additives in functional foods or used as supple-
ments. A more extensive report of flavonoids in common U.S. foods has been pro-
vided by Harnly et al. (2006). Williams and Grayer (2004) presented a detailed
review of the chemistry of the anthocyanins and other flavonoids.
deteRmInAtIon of bIoActIvIty
Many bioactive ingredients have been discovered by assessing traditional folk medi-
cine and remedies. Rich sources of potential bioactive ingredients have come from
traditional Chinese medicine, Ayurveda, and Native American traditional medi-
cines. The breadth of treatments also means a variety of ways have been developed
to assess the potential health benefits of functional foods. When we consider the
thousands of ingredients or components in traditional foods, alternative medicine
formulations, and the potential combinations of materials, the amount of testing
to validate efficacy is staggering. As a result, short-term model systems have been
developed as screening tools for various health conditions. For example, lung tissue
can be used to assess antioxidant regimens that protect the lung, and liver cell models
can be used for hepatic function studies.
Frequently, the cell culture models are employed to screen large numbers of
candidate materials and fractions of materials to identify which component is most
bioactive in the product. The next level of testing is usually small animals (usually
rodents), which serve to assess if the material identified by cell culture is absorbed in
the animals and carried to the target site for the bioactivity. The small animal screen-
ing also serves as an excellent test to ensure that the component tested does not cause
