Ever wonder what natural compounds account for the aroma, flavor and color of vegetables and fruits?

The answer is flavonoids. Thousands of them.

How do we get them? Choose foods by the colour code

Interest by the public in flavonoids has been increasing due to the growing reputation of food antioxidant that can have beneficial roles in disease prevention.

Five Fun Flavonoid Facts

#1. Flavonoids are a large subfamily of phenolic compounds synthesized by plants as pigments that attract pollinators, repel pests and protect plant cells both from ultraviolet radiation and internal production of reactive oxygen species during photosynthesis.

#2. As a group, flavonoids are the most associated

phytochemical class with antioxidant values in plant foods.

Scientists are keenly pursuing numerous potential health effects of flavonoids associated with colorful fruit and vegetable-rich diets. Even in people without disease, benefits may occur for the cardiovascular system, brain, joints, skin, urinary trac

t and healthy aging.

#3. Many of the biological effects of flavonoids seem to come from their ability to modulate communication between cells, a newly discovered mechanism of flavonoid action in

addition to the more traditionally accepted antioxidant role. Read more about potential flavonoid actions in humans, click!

#4. Scientists are examining flavonoids as “biological response modifiers”, a role where they may alter the body's responses to viruses, allergens, bacteria, carcinogens (cancer agents), inflammatory agents, and oxygen radicals.

#5. There are 6 major groups of dietary flavonoids. Although flavonoids are related by a common chemical structure (called in chemistry, a “phenolic ring”), at least 4,000 variations in flavonoid structure occur, and therefore more than 4,000 individual flavonoids in the plant kingdom!

BONUS! If you are interested, the 6 groups are

i) Anthocyanidins. Also called flavonals. Parent structure to anthocyanins found in red, blue, purple and black berries and grapes. Present in dark wines. Examples: cyanidin, delphinidin.

ii) Flavanols. Found in black and green teas, berries, dark chocolate.

Single structures (“monomers”) are called catechins

whereas

multiple-unit structures (“polymers”) are called proanthocyanidins.

iii) Flavanones. Characteristic of citrus fruits (oranges, grapefruit, lemons),

members of this group include naringenin, silybin and hesperidin.

iv) Flavonols. Found in all plants with bright colors, such as berries, kale (dark green),

broccoli and bell peppers, this group includes quercetin and kaempferol.

v) Flavones. Represented by apigenin and luteolin, flavones are found

in herbs (chamomille, parsley) and subterranean plants like celery and radishes.

vi) Isoflavones. The signature group from soybeans and soy products

(tofu, soy milk), isoflavone members include genistein and daidzein.

Flavonoids in plants

What are Flavonoids? Flavonoids are a diverse group of chemicals found in all plants. About 4000 phytochemicals belong to the flavonoids group. Examples of flavonoids are luteolin, quercetin, blumeatin, tetrahdrooxyflavanone, epigallocatechin gallate, anthocyanins, and tamarixetin. Flavonoids are secondary metabolite products from the phenylpropanoid biosynthetic pathway. All Flavonoids are derived from a chalcone precursor. Function of Flavonoids in plants Flavonoids play a variety of roles in plants. Below are some of their important functions: Plant-microorganism interactions : Flavonoids play roles as signal molecules, phytoalexins, detoxifying agents, and stimulants for germination of spores. Flavonoids may have defensive or stimulant role depending on the microorganisms role in the plant. Pigments : Anthocyanins give the colors of flowers, fruits, and leaves of plants. Flavor : Flavonoids are among an array of the chemicals in plants that give the rich taste of plant products. The flavor may act as repellant or attractant to microorganisms or pests or pollinators. Flavonoids are powerful antioxidants and scanvengers of free radicals. Free radicals cause cellular, and DNA damage in our body and consequently induce age-related diseases suchs as dementia and cancer.
Flavonoids: Antioxidant Activity and Health Benefits

What are flavonoids? Flavonoids are polyphenols abundantly found in fruits, vegetables, and herbs (eg. tea, ginger root). Flavonoids are synthesized only in plants. They are a diverse group of phytochemicals, exceeding four thousand in number. From human nutrition perspective, flavonoids are important components of a healthy diet because of their antioxidant activity. Nevertheless, the antioxidant potency and specific effect of flavonoids in promoting human health varies depending on the flavonoid type (chemical, physical, and structural properties). Among the potent antioxidant flavonoid types are quercetin, catechins and xanthohumol. Flavonoid science is a research area rapidly gaining deeper insight on the health benefit and chemical property of flavonoids. Flavonoids and Their Food Sources Example of dietary flavonoid sources include: Tea: Green, white or black tea are a rich source of flavonoids, especially flavonols (catechin, epicatechin, epigallocatechin, epicatechin gallate). Tea is a good source of quecertin. Onions: The major flavonoid in onions is quercetin. Other flavonoids in onion are kaempferol and myricertin. Honey: Depending on the flower type the bees feed on, honey contains myricertin, and quercetin. Other dietary flavonoid sources are beans, spinach, buckwheat, strawberry, blueberry, rooibos plant. The concentration and composition of flavonoids in plants may vary depending on the growing condition, maturity, plant part, and variety. Health Benefits of Flavonoids Beneficial effects of flavonoids on human health are partly explained by their antioxidant activity. Because of the antioxidative property, it is suggested that flavonoids may delay or prevent the onset of diseases (such as cancer) induced by free radicals. They also inhibit low density lipoprotein (LDL) oxidation by free radicals. Flavonoids have been reported to have negative correlation with incidence of coronary heart disease. Furthermore, flavonoids have anti-bacterial, anti-viral, anti-tumor, anti-inflammatory, antiallergenic, and vasodilatory effect. They also inhibit platelet aggregation.