Uses and Properties of<i>Citrus</i>Flavonoids

TLDR

Flavonoids are widely distributed polyphenols whose antioxidant activity underlies health benefits and, in Citrus, they also contribute to taste modulation and bitterness inhibition in food technology. Citrus flavonoids’ antioxidant power depends on structural features such as the B‑ring dihydroxy motif, a 2,3‑double bond conjugated to a 4‑oxo group, and hydroxyls at positions 3 and 5, and these compounds—especially flavanones, flavones, and flavonols—can also serve as repellents, toxins, or breeding targets for disease‑resistant crops. Citrus flavonoids exhibit anticancer, antiviral, antiinflammatory, capillary‑stabilizing, and platelet‑aggregation‑inhibiting activities. Keywords: free radicals, antioxidant; anticarcinogenic; antiinflammatory; platelet aggregation; antiallergic; analgesic; antimicrobial; food additives.

Abstract

Flavonoids are a widely distributed group of polyphenolic compounds with health-related properties, which are based in their antioxidant activity. These properties have been found to include anticancer, antiviral, antiinflammatory activities, effects on capillary fragility, and an ability to inhibit human platelet aggregation. The antioxidant capacity of any flavonoid will be determined by a combination of the O-dihydroxy structure in the B-ring, the 2,3-double bond in conjugation with a 4-oxo function and the presence of both hydroxyl groups in positions 3 and 5. Flavanones, flavones, and flavonols are the flavonoids present in Citrus, and although flavones and flavonols have been found in low concentrations in Citrus tissues, in relationship to flavanones, these types of compounds have been show to be powerful antioxidants and free radical scavengers. Some Citrus flavonoids can be used directly as repellents or toxins or be used in plant improvement programs to obtain more resistant crops. In addition, some Citrus flavonoids and their derivates, in the field of food technology, are principally known for their ability to provide a bitter or sweet taste and as bitterness inhibitor. Keywords: Free radicals, antioxidant; anticarcinogenic; antiinflammatory; platelet aggregation; antiallergic; analgesic; antimicrobial; food additives