Food Biochemistry and Food Processing

22 Biochemistry of Fruit Processing 533

and Dwyer 1998). Flavonoids are increasingly rec-
ognized as playing potentially important roles in
health, including but not limited to their roles as
antioxidants. Epidemiological studies suggest that
flavonoids may reduce the risk of developing cardio-
vascular diseases and stroke.

Flavanones

The major source of flavanones is citrus fruits and

juices. Flavanones contribute to the flavor of citrus;

for example, naringin, found in grapefruit, provides

the bitter taste, whereas hesperidin, found in oranges,

is tasteless.

Figure 22.7.Chemical structures of fruit flavonoids. The propanoid structure consists of two fused rings. “A” is the
aromatic ring, and “C” is a heterocyclic ring attached by carbon-carbon bond to the “B” ring. The flavonoids differ in
their structure at the “B” and “C” rings.